This study examines hospital characteristics that affect the differential in hospital mortality. Death rates for 1984 Medicare inpatients in acute care hospitals, released by the Health Care Financing Administration in 1986, were analyzed. A confirmatory statistical approach to organizational determinants of hospital mortality was formulated and validated through an empirical examination of 239 hospitals. The findings suggest that the effect of hospital size and specialization on mortality was a spurious one when the effects of other variables were simultaneously controlled. A positive association existed between service intensity and hospital mortality: the more hospital services consumed, the higher the mortality rate. Community attributes accounted for more variance in hospital mortality rates than did organizational attributes. The organizational and community factors studied explained 27 percent of the total variance in hospital mortality.