Born in Pieve di Cadore, in the province of Belluno, on 10 September 1945, Ciotti moved with his family to Turin in 1950. He was ordained priest in 1972 by Cardinal Michele Pellegrino, who assigned him to the parish of the streets of Turin.
Ciotti's involvement with social work started in 1966, when he founded Gruppo Abele (Abel's Group) to follow drug addicts held in Juvenile Detention Centers. In 1982, he founded CNCA, the national network of organizations dedicated to charitable hospitality. In 1987 he was appointed the first president of the Italian League against AIDS (LILA), founded by Franco Grillini and others in 1986. On 25 March 1995 he set up the association Libera (Free), to coordinate efforts by Italian organizations against organized crime.
In 1988 Ciotti started to write for newspapers and specialized magazines dealing with social work and public education. In February 1993 he published the first issue of the monthly magazine Narcomafie (Narcotics Mafias). He has authored several books dealing with educational and social problems, such as Genitori, figli e droga (Parents, Children and Drugs), written in collaboration with Vaccaro, and Chi ha paura delle mele marce, (Who is afraid of Rotten Apples).
