The illicit business side of armed conflict can involve clandestine exports to fund combatants, reselling looted goods on the black market, smuggling weapons and other supplies, sanctions evasion and embargo busting, theft and diversion of humanitarian aid, and covert ‘trading with the enemy’. How does such illicit business affect peace operations in conflict zones, and how do such peace operations, in turn, affect illicit business? This article provides a preliminary answer in the case of the 1992-95 war in Bosnia-Herzegovina. Instead of reinforcing the common tendency simply to ignore or condemn the illicit business side of conflict and its relationship to peace operations, it stresses the more ambiguous and double-edged nature of the issue. Peace operations in Bosnia contributed to illicit business activities, but in some respects illicit business also contributed to a number of peace operation goals, including helping to sustain the civilian population and even bringing an end to the conflict. The end result was actually more of a symbiotic rather than exclusively predatory relationship between peace operations and illicit business activities.