Hostility as measured by the Cook-Medley Hostility (HO) Scale on the Minnesota Multiphasic Personality Inventory has been suggested as a risk factor for coronary heart disease (CHD) and total mortality. This study tested the HO-CHD hypothesis in a sample of 1399 men who entered the University of Minnesota in 1953 and, as part of freshman orientation, completed the MMPI. Current health status was ascertained for 94% of the sample through telephone interviews 33 years later. Higher HO scores did not predict CHD mortality, CHD morbidity, or total mortality either before or after adjustment for baseline risk factors. Among the plausible explanations for these results are that (1) hostility is not a risk factor in all populations, (2) the HO scale at age 19 does not assess a stable psychological characteristic, or (3) the HO scale is not an adequate measure of hostility.