The following programs were evaluated: (1) Jail Education and Treatment (JET), Santa Clara County, CA; (2) Deciding, Educating, Understanding, Counseling and Evaluation (DEUCE), Contra Costa County, CA; (3) Rebuilding, Educating, Awareness, Counseling and Hope (REACH), Los Angeles County, CA; (4) Substance Abuse Intervention Division (SAID), New York, NY; and (5) New Beginnings, Westchester County, NY. Comparison of program participants with control groups, disclosed, inter alia, that: (1) controls were significantly more likely than program participants to be reconvicted at least once; (2) the proportion with two or more convictions was almost identical for the two groups; and (3) the three California programs had better outcomes than did the two in New York, displaying modest yet consistent evidence that jail drug treatment is associated with lower chances of recidivism during the follow-up period. The author also examined recidivism probabilities with regard to gender, recent conviction history, age, race/ethnicity, prior drug use, type of program termination, and length of time in program. Tables, figure, references, endnotes