The relationship of level of baseline serum cholesterol to the seven-year incidence of death from all causes and from specific causes was examined in a cohort of 11,121 Yugoslav males aged 35--62 years at the time of their initial examination (1964--1965). Serum cholesterol was negatively related to mortality, i.e., those with a lower cholesterol experienced a higher mortality than those with a higher cholesterol. The negative relationship was significant (as assessed by logistic regression) and remained significant after adjusting for obesity, systolic blood pressure, cigarette smoking, age, history of intestinal parasitism, and socioeconomic status (as measured by years of education). The negative association of serum cholesterol and subsequent mortality appeared to be due to the relationship of cholesterol to deaths due to cancer and to deaths due to respiratory disease (tuberculosis and cor pulmonale). The cancer death-serum cholesterol relationship was not statistically significant but the respiratory disease death-serum cholesterol relationship was. Serum cholesterol, as expected, was positively related to the incidence of coronary heart disease death.