The purpose of this study was to assess the independent association of physical illness and functional limitations with suicide mortality risk. The Cox proportional hazards model was used with data from the 1986–1994 National Health Interview Survey linked to the 1986–1997 National Death Index to analyze the effects of chronic physical illness and functional limitations on suicide deaths (ICD-9 E950–959). After controlling for potential confounders at baseline, functional limitations were shown to be a significant predictor of suicide. Also, psychiatric comorbidity increased the risk of completing suicide. Interestingly, chronic conditions alone were not predictive of suicide completion when functional limitation was added to the model. Implications for the clinical management of suicidal behavior among patients with chronic conditions are discussed.