Forty-five percent of inmates interviewed reported heroin addiction, and/or were found through urinalysis to have used heroin during the previous 48 hours. An additional two percent of the sample reported occasional heroin use. There were significant demographic differences found between addict and nonaddict offenders in terms of personal functioning; nonaddicts reported greater religious affiliation, higher rates of employment, and a higher incidence of having grown up in larger families and smaller towns or cities. More nonaddict than addict offenders reported using marijuana as a first drug. The addicted offenders reported engaging in criminal activity to support their habits; however, nearly half of the addicted offenders also supported their habits at least partially through legal employment. Eighty-eight percent of self-reported addicts believed they could stop using drugs; only 18 percent thought they needed drug treatment to end their abuse. Addict and nonaddict offenders did not differ in the commission of property as opposed to personal crimes; when robbery was excluded from the personal crime category, the difference between addict and nonaddict offenders tended toward significance. 4 tables and 4 references