Illicit drug users, entering a detention center and two psychiatric hospitals in Northern Taiwan, were interviewed for lifetime drug-use-related psychiatric disorders and suicide attempts. Among 197 participants, 17.3%, 16.8%, and 14.2% had a drug-induced psychotic disorder (DIP), a drug-induced mood disorder (DIM), and a history of suicide attempts, respectively. Continuous use of methamphetamine and joblessness were associated with DIP and DIM, accordingly. Polysubstance use was collectively correlated with DIP and DIM. Female gender and history of having any mood disorder were predictors of suicide. These results provide useful clues for detecting drug-related psychiatric disorders and suicide among illicit drug users. The study's limitations are noted.