Awareness of negative consequences of cocaine use is theoretically important for motivation for treatment and relapse prevention. This study reports on the development of an instrument designed to assess cocaine users' self-reported negative consequences of cocaine use. Two samples of cocaine users in treatment for substance abuse completed the Cocaine Negative Consequences Checklist (CNCC). The measure, which is unidimensional in nature with four content area subscales that may be scored, was found to possess excellent reliability across the two samples. The convergent and discriminant validity of the CNCC was supported by the pattern of relationships with other measures of cocaine consequences, cocaine use, the Addiction Severity Index, and with demographic measures. Further research is needed on the utility of this measure in treatment and research.