This study applied an epidemiologic case-control design to the identification of variables predicting which subjects in a population of recreational drug users were likely to have a felony conviction. A sample of 158 self-identified drug users responded to the web-based DRUGNET survey from February, 1997 through June, 1998. In this sample of 704 U.S. citizens who reported using illicit drugs, 79 (11.2%) reported having a drug-related felony conviction. A further 52 (7.4%) subjects reported felony convictions not related to drugs. Control subjects were drawn from the same sample and matched to cases on sex, age, and ethnicity. Subjects with drug-related convictions differed significantly from controls on 13 variables and those with nondrug-related convictions differed on 11 variables out of the 82 used in this study. Although there are major limitations given the self-selection of the sample, the differences between the groups indicates that we should be wary in generalizing from the minority of drug users who are arrested or incarcerated to the population of drug users in general.