Insight and hopelessness have been reported to be associated with suicidality in schizophrenia. In addition, there is evidence that diminished insight is correlated with impairment in some domains of cognitive function in schizophrenia. The purpose of this study was to clarify the relative importance for suicidality in patients with schizophrenia of hopelessness, cognitive dysfunction, and insight. This study included 333 patients with chronic schizophrenia who were prospectively studied. Insight was rated by the insight items from the Schedule for Affective Disorders and Schizophrenia (SADS) and the Hamilton Depression Rating Scale (HDRS). Positive, negative, and anxiety-depression symptoms were measured with the Brief Psychiatric Rating Scale (BPRS). Cognition was assessed with a neurocognitive battery, which included measures of attention and psychomotor speed, verbal fluency, verbal memory, working memory, and executive function. Current and lifetime suicidality was prospectively assessed. Hopelessness, substance abuse, and greater insight were associated with attempted suicide and suicidal ideation. Those with a history of lifetime, but not current, suicidality had better function on tests of psychomotor speed and attention, verbal working memory, verbal fluency, verbal memory, and executive function. Neurocognitive measures were not significantly correlated with hopelessness and insight. Hopelessness was more severe in those with current and lifetime suicidality. A multiple regression analysis was used to predict current and lifetime suicidality from hopelessness, substance abuse, insight, and cognitive factor scores. The regression models predicting current and lifetime suicidality indicated that hopelessness was the most important predictor of both (beta=0.41, p=0.0001; and beta=0.35, p=0.01, respectively). These findings suggest that hopelessness, substance abuse, greater insight into illness, and higher cognitive function are associated with greater suicidality in chronic schizophrenia, but that among these, hopelessness may be the principal predictor of suicidality.