Suicide-related behavior (SRB), including suicide attempts and instrumental SRB, occurs far more often than completed suicide and exacts a toll on patients, their loved ones, and society. Nevertheless, few prospective studies of SRB have been conducted. In this study, 954 patients were interviewed in a psychiatric hospital and then followed for one year after discharge. During this one-year period, nearly one-quarter of patients (23%) engaged in SRB, with the rate of suicide attempts (18%) three times greater than the rate of instrumental SRB (5%). Risk factors for SRB were demographic (White ethnicity, female gender), clinical (past SRB, depression, impaired functioning), and contextual (unemployment, large social networks). In contrast with other studies, there was no "peak" in the risk of SRB shortly after hospital discharge. Instead, patients' rate of SRB was relatively constant over the one-year follow-up. Implications for risk assessment and management in acute inpatient settings are discussed.