In the 2020 season, Avcı took over Trabzonspor and led the team to become Süper Lig champions in the 2021–22 season. On 7 March 2023, Avcı announced his resignation from his position.
Following the end of his professional football career in 1999, he completed coaching courses and obtained a Professional License.
Managerial career
İstanbulspor
He started his coaching career in İstanbulspor, where he played football for a long time, as one of Ziya Doğan's coaches in the 1999–2000 season. Towards the end of the season, he was brought to the head of the team together with football player-managerAykut Kocaman and coached the team for 7 matches. He worked as Aykut Kocaman's assistant until 2002. He was appointed as the head of the İstanbulspor U–21 team in the 2002–03 season. They came third in the U21 Ligi. In 2003, he took charge as "Youth Development Technical Officer".
Under his leadership, the team advanced to the elite round of the tournament by finishing in first place in their qualifying group. In the elite round, they won all three matches, but suffered their first defeat against Italy in the tournament. However, they bounced back by defeating England and Belarus to secure the group runner-up spot. In the knockout stage, they defeated Croatia in the semi-finals and Netherlands in the final to become the European Champion for the second time in their history. Tevfik Köse was the top scorer of the tournament, while Nuri Şahin was named the best player. Caner Erkin and Onur Recep Kıvrak were among the team members who would later play for the Turkey national football team.
Their success in the championship qualified them to participate in the 2005 FIFA U-17 World Championship. In their first-ever appearance in the tournament, they won all three group matches and reached the quarter-finals, where they eliminated China. However, they were eliminated in the semi-finals after conceding a goal in the 90th minute. In the match for third place, they lost 2–1 to the Netherlands, finishing in fourth place overall. Throughout his one-year tenure, he coached the team in 27 matches, winning 18, drawing 5, and losing only 4 times.
İstanbul Başakşehir (formerly known as Istanbul BB)
Under Avcı's leadership, İstanbul Başakşehir (formerly known as Istanbul BB) reached the final of the 2010–11 Turkish Cup. However, in the final match against Beşiktaş, they drew in regular time, and Beşiktaş won the cup as a result of penalties. In addition to his successful stint at İstanbul Başakşehir (formerly known as Istanbul BB) Abdullah Avcı received a contract from the Turkey national team. On November 18, 2011, he left İstanbul Başakşehir to join the national team.
Turkey national team
On 17 November 2011, after Guus Hiddink left his job, he was appointed as the coach of the Turkey national football team, which was vacated. A contract was signed with Avcı until 21 May 2015. Having failed with only 6 wins and 4 draws in 18 matches with the national team, Avcı resigned from his position on August 20, 2013, after the rumors of the search for a new coach were not denied.
During his time with İstanbul Başakşehir, Avcı helped to establish the team as a strong competitor in the Süper Lig. He was known for his tactical acumen and ability to develop young players. However, On 30 June 2019, Avcı parted ways with the club to join the Turkish giants club, Beşiktaş.
Beşiktaş
On 3 July 2019, Avcı signed a three-year contract with Beşiktaş, one of the biggest football clubs in Turkey. He began his tenure with the team, but his performance and tactics were heavily criticized by the fans who were not satisfied with the team's results and playing style. Despite winning 11 matches at the start of the season, Beşiktaş's performance declined significantly, which led to Avcı's sacking on 25 January 2020, after only seven months as the coach. It is worth noting that the team's disappointing results and the lack of support from the fans played a significant role in Avcı's departure from the club.
Trabzonspor
On 10 November 2020 Avcı signed a 2.5-year contract with Trabzonspor. Trabzonspor is a football team based in the city of Trabzon, Turkey. They had not won the Süper Lig championship for 36 years until Avcı's tenure. Avcı led Trabzonspor to win the 2020 Turkish Super Cup on 27 January 2021, and later on 30 April 022, they won the Süper Lig championship three weeks before the end of the 2021–22 season by drawing 2–2 with Antalyaspor. During his time with Trabzonspor, they had a successful home record, as they went unbeaten for 36 home games. However, on 4 March 2023, Trabzonspor lost their first home game under Avcı's management to Ümraniyespor.
On 7 March 2023, Avcı resigned from his position as Trabzonspor coach for personal reasons, leaving behind a successful legacy.
