OBJECTIVE To evaluate the changes over time in quality and quantity of coping skills acquired following cognitive behavioral therapy (CBT), and examine potential mediating effects on substance use outcomes. METHODS A randomized controlled trial (RCT) evaluating the effectiveness of a computerized version of CBT (CBT4CBT) as an adjunct to standard out-patient treatment over an 8-week period. METHODS Data were collected from individuals seeking treatment for substance dependence in an out-patient community setting. METHODS Fifty-two substance abusing individuals (50% African American), with an average age of 42 years, and a majority reporting cocaine as their primary drug of choice. METHODS Participants' responses to behavioral role-plays of situations associated with high risk for drug and alcohol use were audio-taped and rated independently to assess their coping responses. RESULTS There were statistically significant increases in mean ratings of the quality of participants' coping responses for those assigned to CBT4CBT compared to treatment as usual, and these differences remained significant 3 months after treatment completion. Moreover, quality of coping responses mediated the effect of treatment on participants' duration of abstinence during the follow-up period. CONCLUSIONS These findings suggest that assignment to the computerized CBT program improved participants' coping skills, as measured by independent ratings of a role-playing task. It is also the first study to test and support quality of coping skills acquired as a mediator of the effect of CBT for substance use.