War-torn societies are often racked with generalized distrust, both among citizens and between citizens and the state. Even long after conflict ends, former combatants who participated in violence and challenged the state’s monopoly on the legitimate use of force may have an especially unsettled relationship with the state. After demobilization, their potential relapse into armed struggle is thought to pose a severe risk to security and stability. What factors determine ex-combatants’ degree oftrust in the state after their demobilization? We present the first empirical examination of this question through a survey of 1,485 former members of paramilitary and guerrilla groups in Colombia. We find limited support for social theories of trust: our analysis indicates that participation in civic and association life has no discernible impact on ex-combatants’ trust in the state. However, contrary to the warnings of disarmament, demobilization and reintegration (DDR) practitioners, continuing connection between former fighters has a neutral to positive impact on trust, especially for former guerrilla. We find that intense socialization within the armed group during wartime has a corrosive impact on trust in the state, even years after demobilization. This finding suggests that the formation of “anti-socialcapital” may be difficult to reverse. With respect to institutional theories of trust, ex-combatants who perceive that the state performs well in important policy areas, such as the protection of civil and political rights, exhibit stronger trust. However, while conventional wisdom holds that ex-combatants are principally interested in material benefits we find no relationship between individual measures of well-being, including unemployment, and lower levels of trust in the state.