Data were obtained on four dimensions of criminal activity (frequency, variety, severity, and income) from male and female prisoners (N = 200) with preincarceration heroin dependence who participated in a randomized clinical trial of buprenorphine treatment. The article examines the above-mentioned dimensions of crime and their relationships with demographic characteristics, substance use, legitimate employment, drug treatment episodes, and psychological problems. Results largely show several important similarities to results on previous prison inmate cohorts with histories of heroin addiction, although the present sample may have more of a tendency toward violent crime than earlier cohorts of heroin-dependent offenders. This study’s findings may have implications for the design of appropriate treatment interventions for prisoners with preincarceration heroin dependence that address not only substance use but also criminal activity.