The dynamic relationships among drug use, drug dealing, lifestyles, and crime were examined by interviewing probationers in three Northern Virginia counties. Results of the interviews showed that drug dealing had a positive effect on both property crime and violent crime while drug use had a significant effect only on property crime. It was also found that a significant number of drug offenders were involved in both the use and sale of drugs, which, in essence, had a powerful effect on other types of criminal activities. Additionally, results of the study revealed that the impact of drug use and drug dealing on crime was modified by individual lifestyles. Theoretical and policy implications of these findings are discussed.