Drug corruption is more likely among law enforcement officers who use undercover investigative methods. Current views of police corruption attribute drug corruption either to flaws in character or to the corrupting criminal environment where investigations are carried out. This article presents a pragmatic approach to the interaction between personality and situational causes, and findings from an assessment of a large group of undercover agents. Greater drug/alcohol abuse and disciplinary problems were linked to amount of undercover work. For the majority of agents, the risk for drug corruption was related to either poor impulse control, Neuroticism, or a desire to experiment with new experiences. Agents assessed as having a Disciplined Self-Image presented a lower risk for drug corruption while also showing risk taking and motivational qualities required for successful undercover performances. Certain personality traits of interest may only manifest themselves as disciplined or undisciplined conduct when given the opportunity by an instigating environment.