Mid 1980s, Stojanović returned to Yugoslavia and worked as a director in a theatre. He was one of the founders of "The Time" [VREME] magazine for which he also wrote as a journalist. From the beginning of the 1990s, he was an anti-war activist. He worked as journalist for "Ship" [Brod] radio, and later as a freelancer for "Radio France Internationale." In 1994, he left the country and moved to New York City. In the US, he worked as a translator and was a guest lecturer at several American universities. After the conflict in Kosovo at the end of the 1990s, Stojanović worked for the OSCE and UN missions from 2000 until 2006. During this period he also shoot several documentaries about Serbian war crimes and war criminals. Lazar Stojanović returned to Serbia in 2011 and worked for the Humanitarian Law Center as Coordinator of the Public Campaign for the Regional Truth Commission project (RECOM).