Illicit drug users are generally considered both patients and criminals in Taiwan. This study presents drug use behaviors and criminal recidivism of male subjects incarcerated for illicit drug use in Taiwan after detoxification at a detention center. This study also examined the relationship between drug use behaviors and subsequent recidivism. Charts and crime records of 794 male patients from the acute detoxification unit in a detention center in northern Taiwan were reviewed. These subjects were incarcerated for methamphetamine or/and heroin use. The authors examined the relationship between the variables collected during detoxification and subsequent recidivism of illicit drug use in the following 5 years after detoxification. Of 794 subjects, 539 (67.9%) were repeat offenders during the following 5 years after detoxification. Their recidivism occurred primarily within the first 2 years after being released into the community. The recidivism rate for heroin users was significantly higher than that of methamphetamine users. Aged under 30 years, a previous criminal record, and a positive urine analyses test for illicit drugs upon entering the detoxification unit were significantly associated with recidivism. Recidivism rates of illicit drug users in Taiwan after detoxification in the detention center were substantially high. The efficacy of detoxification programs at detention centers in Taiwan needs to be re-evaluated.