Many contemporary civil wars are characterised by a political economy of violence – a 'war economy' – whose actors are highly motivated by profit. Examining cases of Afghanistan and Bosnia-Herzegovina, this article draws attention to a different but related notion: criminal economic activities which characterise the political economy of violence during civil war develop a self-serving momentum and continue, after 'resolution' of the political conflict, to do great harm. The article explores the impact of illegal money-making – a legacy of the 'war economy' – on societies in post-conflict transition. It suggests that, in some conflict resolution efforts, the pressure to impose a 'political' resolution causes peacebuilders to neglect this legacy and so threatens the peacebuilding agenda.