We sought to identify behavioral factors associated with response to an employment-based intervention in which participants had to provide drug-free urine samples to gain access to paid employment. The present secondary analysis included data from a randomized clinical trial. The trial evaluated whether employment-based reinforcement could decrease cocaine use in community methadone patients. Participants (N = 56) in the trial worked in a model workplace for 4 hr every weekday and earned about $10 per hr. After a 4-week baseline, participants were randomly assigned to an abstinence-and-work (n = 28) or work-only (n = 28) condition and could work for an additional 26 weeks. Abstinence-and-work participants had to provide cocaine-negative urine samples to work and maintain maximum pay. Work-only participants only had to work to earn pay. For work-only participants, cocaine abstinence during baseline and the intervention period were significantly correlated (rs = .72, p < .001). For abstinence-and-work participants, baseline opiate abstinence was significantly correlated (rs = .59, p < .001) and workplace attendance was marginally correlated (rs = .32, p = .098) with cocaine abstinence during the intervention period. Furthermore, participants who provided over 60% cocaine-negative urine samples during the intervention period (i.e., responders) had significantly higher baseline rates of opiate abstinence (p < .0001) and workplace attendance (p = .042) than did nonresponders. Employment-based reinforcement of cocaine abstinence may be improved by increasing opiate abstinence and workplace attendance prior to initiating the cocaine-abstinence intervention.