Although many clinical observations suggest that Hope influences the onset, duration, prognosis, and recovery from mental and physical illnesses, a lack of direct scientific proof persists because no method exists for the objective assessment of hope. We have now constructed the Hope Index Scale, a testing instrument for the measurement of this rather elusive human attribute. Upon testing control and experimental subjects, it was found that score distribution on the Hope Index Scale correlates negatively with Beck's Hopelessness Scale (Pearson r = −.88, P <.001) and is independent of age, race, or sex. It is concluded that this tool can help identify individuals with varying degrees of psychosocial problems and that scores of 150 or below are indicative of pathologic hope deficit often associated with suicide.