In order to advance the detection and prevention of suicide, recent research has focused on predictors of suicidal ideation and behavior such as negative cognitive styles, dysfunctional attitudes, hopelessness, and rumination. In this study the relationships among these risk factors in the context of the Attention Mediated Hopelessness (AMH) theory of depression are examined. One hundred and twenty-seven undergraduates in the Cognitive Vulnerability to Depression (CVD) project were followed for 2.5 years. The CVD project followed initially nondepressed freshmen, at either high or low cognitive risk for depression, in order to predict onsets and recurrences of depressive disorders. The presence and duration of suicidal ideation were predicted prospectively by rumination and hopelessness, and hopelessness partially mediated the relationship between rumination and ideation and fully mediated the association between rumination and duration of suicidality. Further, rumination mediated the relationship between cognitive vulnerability and suicidal ideation.