This article considers what demobilisation, disarmament, and reintegration (DDR) programmes might learn from research on gangs and the problems associated with government-instituted 'wars on gangs' putatively aimed at reducing or fighting gang-related violence. It begins by considering interventions associated with the global war on gangs, and compares their underlying premises and practices with those of DDR programmes while highlighting how both are plagued with problems associated with drawing on de-contextualized templates. Drawing on long-term ethnographic research carried out in Nicaragua and South Africa, the article then goes on to explore why individuals leave gangs, focusing in particular on the more organic processes that deplete gangs of their members, as well as the consequences that the different possible occupational trajectories of ex-gang members can have for patterns of violence. These offer a number of potential lessons for DDR programmes, particularly with regard to reducing violence in a realistic and sustainable manner.