The research used bivariate and multivariate techniques to examine data from urinalyses for 724 men and 136 women during the program’s first year in 1988 and 1,270 men and 286 women during the program’s second year in 1999. Results revealed that men had more extensive drug histories, whereas women had a higher average number of both positive tests for any drug and tests revealing multiple substances. Women had at least twice as many positives for both types of tests used. The findings for the second year were similar to those in the Drug Use Forecasting results and indicated that this pattern among females may be a national trend. Findings also indicated that female offenders under community supervision in Jefferson County had substantial drug abuse problems. Findings suggested that females had a more pronounced and persistent addiction problem than did male offenders. Discussion of these findings with drug treatment staff also confirmed that female drug abusers had special problems, including the lack of job training and work experience. Findings indicated that programs must address gender differences and not simply handle males and females in the same manner. However, more research into gender differences in this population is necessary to establish clear conclusions. Tables and 29 references