This study tested whether feelings of defeat and entrapment mediated the effects of negative appraisals upon suicidal ideation and behavior. A sample of 93 university students who reported some degree of suicidal ideation completed questionnaires of negative appraisals of social-support and problem-solving, defeat, entrapment, hopelessness and suicidality. The results supported a model whereby defeat and entrapment fully mediated the effect of appraisals of social support and problem-solving ability upon suicidality. Furthermore, controlling for hopelessness had no substantive impact upon this model. The findings support socio-cognitive models of suicidal behavior and highlight the key role of defeat and entrapment in suicide. The clinical implications of these findings are discussed.