Criminal recidivism was studied during 2 years in a Swedish population-based cohort (N = 318) of mentally disordered male offenders who had undergone a pretrial forensic psychiatric investigation, been convicted in subsequent trials, and been sentenced to forensic psychiatric treatment (FPT; n = 152), prison (n = 116), or noncustodial sanctions (n = 50). Recidivism was analysed in relation to index sanctions, levels of supervision, diagnoses, and criminological factors. Significantly lower recidivism in the FPT group was related to lower crime rates during periods at conditional liberty in this group alone, and recidivism was significantly more common among offenders with at least one of the two diagnoses of substance abuse disorder and personality disorder than among those with psychotic or other mental disorders alone. Age at index crime and number of previous crimes emerged as significant predictors of recidivism. The results of this study suggest that the relapse rates depend as much on level of supervision as on individual characteristics.