The increase in trafficking of illegal drugs in North America has led to an expansion in the numbers of law enforcement officers and a corresponding increase in the risk of drug corruption among those officers, particularly those working undercover. Currently drug corruption is attributed to either flaws in character or to the corrupting criminal environment where investigations are carried out. The results of an assessment of a group of undercover agents show that greater drug/alcohol abuse and disciplinary problems were linked to the amount of undercover work and the risk of drug corruption as related to either poor impulse control, neuroticism, or a desire to experience new sensations. Those agents having a disciplined self-image presented a lower risk for corruption while still showing risk taking and motivational qualities which are necessary for survival as an undercover agent. The article concludes that certain personality traits may only manifest themselves as disciplined or undisciplined conduct when given the opportunity by an instigating environment. 1 table and 22 references (Author abstract modified)