Xã hội đen, (chữ Nôm: 社會顛, literally means "black societies"), is a Vietnamese term used to describe criminal underworld. The term is believed to have become widely used thanks to Hong Kong TV series and movies about the Chinese secret society of Heishehui (Chinese: 黑社会).^[1] An individual who participates in these criminal activities can be called a giang hồ,^[a] găng-xtơ,^[b] côn đồ,^[c] or tội phạm;^[d] while a criminal organization is known as băng đảng or băng nhóm, depending on its scale.^[2][3] They are those whose goal is to make money from illegal and overall immoral activities.

According to the law of the Socialist Republic of Vietnam, under Clause 1, Article 8 of the 2015 Criminal Code:^[4]

A crime means an act that is dangerous for society and defined in Criminal Code, is committed by a person who has criminal capacity of corporate legal entity, whether deliberately or involuntarily, infringes the sovereignty and territorial integrity of the nation, infringes the political regime, economic regime, culture, national defense and security, social order and safety, the lawful rights and interests of organizations, human rights, the lawful rights and interests of citizens, other aspects of socialist law, and leads to criminal prosecution as prescribed by this Code.

Joining a criminal organization is considered to be a "very serious crime" in Vietnam.^[5] For example, a person who illegally transported goods or money across the border could "face a penalty of up to 2 years community sentence or 3–24 months' imprisonment;"^[e] but the same crime if committed by a member of an organized group would be liable for "a penalty of 2–5 years' imprisonment."^[f]

Although the law would also make political groups, such as Việt Tân^[6] and DTVNCH,^[7][8] criminal organizations,^[g] they are not part of xã hội đen as their stated aim and genesis is ideological rather than commercial.

Small group of criminals, băng nhóm, has simple structure. It is organized loosely with a small number of members. The leader is called đại ca or băng trưởng. They act aggressively and mostly commit crimes such as murder, robbery, theft, and fraud. These small groups may band together to form a larger syndicate or find protectorate from an already existed one.^[9][3]

A larger criminal syndicate, băng đảng, has a clearer, more sustainable organizational structure with long-term operational goals. The leadership can have one or multiple people, but there is one individual at the top known as trùm. Below them is the command level with people who would be in charge of smaller groups within the syndicate. Ordinary members, known as đàn em, are those who directly carry out criminal acts, as well as all tasks assigned by the leaders.

For example, during the 1960s in South Vietnam, there was a powerful gang led by the infamous Đại Cathay, the trùm of his gang and the "Brother of all brothers" (Vietnamese: Đại ca của các đại ca).^[10][11] Along Đại were several members that assisted his leadership: cánh tay trái "H đầu bò" (H the bull head), cánh tay phải "Lâm chín ngón" (Lâm the nine fingers), and quân sư "Hoàng guitar" (Hoàng the guitarist).^[12][13] The gang bosses that submitted to Đại Cathay were Huỳnh Tỳ and Ngô Cái, who were respectively known as "Second Brother"^[h] and "Third Brother"^[i].^[14][15]

Vietnamese drug lords control territories in the northwestern provinces. Because Vietnam is located near the Golden Triangle, its heroin trade is concentrated along its borders with Laos and Cambodia.^[16] Since 2019, not only has Vietnam become a drug market but also a transit port that criminals use to traffick drug to other countries.^[17]

Meanwhile, Vietnamese illegal trafficking groups control areas in Hồ Chí Minh City. Their networks have been linked to the human-trafficking and human-smuggling markets, the ivory- and pangolin-trafficking markets, illicit logging operations, arms trafficking, and drug-trafficking markets.^[18]

Foreign-based gangs such as the Korean mafia^[23][24][25] and the Japanese yakuza^[26] are also reported to have activities in Vietnam.

In 1865, the China-based brigand Black Flag Army crossed the border from Guangxi into northern Vietnam, created a profitable extortion network along the course of the Red River. The group later joined forces with the Qing and the Nguyễn to fight off the French.

In 1945, various groups of gangsters unified into an organization called Bình Xuyên, led by Ba Dương. Before that, in the 1920s, Ba Dương was already the leader of a coalition of river pirates. In 1949, Bình Xuyên became a legitimate military organization. In 1954, Bình Xuyên controlled nearly the entire supply of opium of Vietnam. In 1955, Bình Xuyên was defeated in the Battle of Saigon and was disbanded.

Saigon in the 1960s saw the rise of four powerful Vietnamese gangs, whose leaders are known as "Four Great Kings" (Vietnamese: Tứ đại thiên vương) and were behide almost all of criminal activities and rackets within the city:^[27]

• Lê Văn Đại (nicknamed "Đại Cathay") was the son of Lê Văn Cự, a member of Bình Xuyên group who died in around 1946. At the age of 14, he ran away from home and made a living by shining shoes and selling newspaper near Cathay cinema. He quickly built himself a loyal gang group, defeated his rivals, and became the top of the "Four Great Kings" of Saigon's criminal underworld before 1975.^[10][11]
• Nguyễn Thuận Lai (nicknamed "Huỳnh Tỳ") used to be a gentle and hard-working student who loved poetry. After grade 10, he went out to work and started to involved in criminal activities. He rose up to become the most powerful gang boss until 1964, when he and his gang had to submit to Đại Cathay.^[14][28]
• Ngô Văn Cái was known for his skillful martial art. He was considered to be the "Third Brother", after Đại Cathay and Huỳnh Tỳ. He later married and involved less in criminal activities. Thus, managed to stay out of trouble with the government.^[15]
• Nguyễn Kế Thế (nicknamed "Ba Thế") was known to be the person that kicked Đại Cathay down the stairs, provoked a war between the then Tỳ-Cái-Thế kings and Đại Cathay.

Beside the "Four Kings", there was also an infamous Chinese crime boss called Tín Mã Nàm (nicknamed "Mad Horse"). He was considered as the "Triad King"^[n] of Chợ Lớn and was said to be the second highest-ranking member of Hồng Môn, a triad from China, behind only Hoàng Long ("Yellow Dragon").^[13][29]

In 1964, Đại Cathay's gang and Tín Mã Nàm's triad clashed in a bloody fight. Although Mã Nàm won, the battle had caused many people to avoid his casinos and his business sharply declined. Tín Mã Nàm was then forced to call for a negotiation with Đại where he and many of the Chinese gangs in Chợ Lớn decided to give up away the areas between Nancy market and District 1 to Đại Cathay's gang.^[30][31]

In 1966, Tạ Vinh, a Chinese businessman, was arrested due to some conflicts with the government. Triads in Chợ Lớn and Hongkong tried to intervene by sending a petition to the embassy of the Republic of Vietnam in Taipei, Taiwan, but failed. Tạ Vinh was publicly executed on March 14.^{[32][33][34][35]}

In November 1966, Đại Cathay was arrested and placed in Phú Quốc Prison. On January 7 of 1967, Đại and his men escaped from the camp, but when he passed through the front gate, the alarmed sound, alerting the guards surrounding the prison. Discovered, Đại was chased to the North part of the island, but the guards never found him and he was never heard from again.^[31]

Following 1975 and the reunification of Vietnam, the era of Four Great Kings of Saigon came to the end. This, however, had allowed Năm Cam, a former follower of Đại Cathay, to developed a powerful criminal organization and dominated the South. He is said to have gone on a 15-year long killing spree in order to eliminate his rivals, and is considered as the "Godfather" of Vietnam.

Meanwhile in the North, four crime bosses also appeared:

• Dương Văn Khánh (nicknamed "Khánh Trắng"), whose group operated in Hanoi under a legal named "Đồng Xuân Labor Union." At its height, Khánh Trắng's organization even received praise from government officials as a model example of an organization that should be replicated. He and his members was finally arrested on 24 May 1996 and Khánh was sentenced to death.
• Nguyễn Thị Phúc (nicknamed "Phúc Bồ") operated in Hanoi, around Đồng Xuân market. Phúc Bồ occasionally classed with Khánh Trắng until her arrest in 1996. She was released in 2002.
• Dung Hà, a high-ranking gangster in Haiphong, was considered one of the two greatest mafia bosses of the Vietnamese underworld, along with Năm Cam.
• Hải Bánh, a follower of Dung Hà until 1995, when Hà was temporary arrested. After that, Hải and some members went to the South and joined Năm Cam's gang.

At one point, both Năm Cam and Dung Hà joined forces to attack Lê Ngọc Lâm (nicknamed "Lâm chín ngón"), another former member of Đại Cathay. In 2000, Dung Hà was assassinated as she tried to expand her operation to Hồ Chí Minh City. In 2001, both Năm Cam and Hải Bánh, along with other gang members were arrested. Cam was executed while Hải was imprisoned until 2022.^[20][21]

• Born to Kill
• Tran Organization

Vietnamese-American gangs had their genesis in southern California, typically commit home invasion robbery against Vietnamese and other Asian refugee families. The kidnapping of young girls is also common with many are forced into having sex, doing drugs, and committing criminal offenses.^[36] Vietnamese gangs are known to be highly mobile, often travel interstate, perpetrating a variety of criminal acts in a short period of time. They are considered to be less organized but more violent than ethnic Chinese organized crime groups. Ethnic Chinese from Vietnam (sometimes called Viet-ching) often play an important role as members of Vietnamese gangs or as links between Vietnamese and Chinese criminal organizations^[37]

• Red Scorpions

Vietnamese gangs have emerged as dominant and violent criminal organizations in Toronto's Chinatown area, with many of them were hired by already-established Chinese triads to work as street enforcers. While for the most part, these gangs have on businesses within their community, it seems that they are looking to expand their activities to the outside business community. There are three levels in Vietnamese criminal organizations. First is the organized crime level representing the geographically anchored hierarchy, second is the street gang level which carries out directions from the organized crime level leadership, and last is the action-set which consists of young males aspiring to gain membership in the street gangs.^[38]

• 5T (gang)

There has been concern expressed about the growth of ethnic Vietnamese criminal groups in Australia for a decade. Vietnamese gangs are heavily armed and have established links with Australian crime figures. They mainly involve in crimes against their own community including murder, extortion, robbery and petty drug dealing, with standover and extortion being the most common. Vietnamese criminal organizations are known to organize heroin shipments, either independently of or in association with established Chinese heroin trafficking operations. An increasing amount of heroin coming to Australia appears to have been transhipped through Vietnam. Australian polices have significant difficulties in counteracting Vietnamese organised crime due to a lack of Vietnamese police officers, consequent language barriers, and a common mistrust of government agencies by migrants from Vietnam.^[37]

• Ông trùm (The crime boss) [vi]
• Mùa cúc susi (Susi's chrysanthemum season) [vi]
• Mê cung (The maze) [vi]
• Người phán xử (The Arbitrator) [vi]
• Bụi đời Chợ Lớn (Gangsters of Chợ Lớn) [vi]
• Bẫy rồng (Clash) [vi]
• Giang hồ Chợ Mới (New Market's gypsies) [vi]

The impact of gangsters such as Đại Cathay and Năm Cam has created a generation that admired the xã hội đen culture. One notable example is Khá Bảnh, a YouTuber known for creating videos that showed him as a man of honor who possesses many moral principles of a giang hồ.^[39][40]

• List of criminal enterprises, gangs, and syndicates