<i>Background:</i> Suicide is a serious public health problem. In the international literature there is evidence to support the notion that certain temperaments and personality traits are often associated with suicidal behavior. <i>Sampling and Methods:</i> In this study, 150 psychiatric inpatients were investigated using the Temperament Evaluation of Memphis, Pisa, Paris and San Diego autoquestionnaire, the Minnesota Multiphasic Personality Inventory, 2nd edition (MMPI-2) and the Beck Hopelessness Scale and evaluated for suicide risk by means of the critical items of the Mini International Neuropsychiatric Interview. <i>Results:</i> Statistical analysis, including logistic regression analysis and multiple regression analysis, showed that suicide risk contributed to the prediction of hopelessness. Among the temperaments, only the hyperthymic temperament, as a protective factor, and the dysthymic/cyclothymic/anxious temperament contributed significantly to the prediction of hopelessness. Irritable temperament and social introversion were predictive factors for suicidal risk. Hopelessness and depression were associated with higher suicidal behavior and ideation, but, unexpectedly, depression as measured by the MMPI did not contribute significantly to the multiple regressions. <i>Conclusions:</i> The present study indicated that, although suicidal psychiatric patients have MMPI-2 profiles in the pathological range, they exhibit several differences from nonsuicidal patients. Patients at risk of suicide have specific temperaments as well as personality and defense mechanism profiles. They are more socially introverted, depressed and psychasthenic, and use hysterical and schizoid mechanisms more often. Generalizability of the findings was limited by the small sample size and the mix of bipolar disorder I, bipolar disorder II, major depressive disorder and psychotic disorder patients.