Abstract. Background: For decades we have understood the risk factors for suicide in the general population but have fallen short in understanding what distinguishes the risk for suicide among patients with serious psychiatric conditions. Aims: This prompted us to investigate risk factors for suicidal behavior among psychiatric inpatients. Method: We reviewed all psychiatric hospital admissions (2008–2011) to a centralized psychiatric hospital in Ontario, Canada. Using multivariable logistic regression we evaluated the association between potential risk factors and lifetime history of suicidal behavior, and constructed a model and clinical risk score to predict a history of this behavior. Results: The final risk prediction model for suicidal behavior among psychiatric patients (n = 2,597) included age (in three categories: 60–69 [OR = 0.74, 95% CI = 0.73–0.76], 70–79 [OR = 0.45, 95% CI = 0.44–0.46], 80+ [OR = 0.31, 95% CI = 0.30–.31]), substance use disorder (OR = 1.30, 95% CI = 1.27–1.32), mood disorder (OR = 1.49, 95% CI = 1.47–1.52), personality disorder (OR = 2.30, 95% CI = 2.25–2.36), psychiatric disorders due to general medical condition (OR = 0.52, 95% CI = 0.50–0.55), and schizophrenia (OR = 0.42, 95% CI = 0.41–0.43). The risk score constructed from the risk prediction model ranges from −9 (lowest risk, 0% predicted probability of suicidal behavior) to +5 (highest risk, 97% predicted probability). Conclusion: Risk estimation may help guide intensive screening and treatment efforts of psychiatric patients with high risk of suicidal behavior.