Objective: To determine whether the recidivism rate varies for adolescent serious juvenile offenders with bipolar disorder in response to compliance with antimanic medication. Method: Probation records were reviewed for all adolescents (N = 31) released during a 1-year period (April 1, 1993-March 31, 1994) from a county juvenile corrections treatment facility who had DSM-III-R bipolar disorder, were stabilized on medication, and had agreed to continue treatment at an adolescent psychiatry clinic. New offenses and probation violations committed during the 12-month period after release were tallied. These recidivism records were then compared with medical records to ascertain whether these acts were committed while subjects were on (taking) or off (not taking) medication. Results: The number of serious offenses (felonies and misdemeanors) was significantly reduced while subjects were on medication (4 offenses in 2992 days) versus off medication (39 offenses in 6108 days) (p < .0001). The off-medication rate of offending was 4.8 times higher than the on-medication rate. Probation violations were also significantly reduced while subjects were on medication (p < .001). Conclusion: Compliance with prescribed antimanic medication can markedly decrease recidivism in serious juvenile delinquents with bipolar disorder.