The value of serum total cholesterol measurement in predicting coronary heart disease (CHD) is well established in middle-aged men, but has been questioned in middle-aged women and older people of both sexes. To address this, the most recent follow-up data from 25 populations in 22 US and international cohort studies were presented and analyzed at a recent National Heart, Lung, and Blood Institute (NHLBI) workshop. Crude relative and absolute excess risks of fatal CHD were determined for individual studies and pooled across studies to determine pooled risk estimates. Serum total cholesterol and low-density-lipoprotein (LDL) cholesterol levels predicted fatal CHD in middle-aged (< 65 years) and older (> or = 65 years) men and women, though the strength and consistency of these relationships in older women were diminished. High-density-lipoprotein (HDL) cholesterol levels inversely predicted CHD in middle-aged men and women and in older women, but not in older men. Data for minority groups and for overseas populations were similar to those for white people in the United States. Relative risk estimates were generally lower for older than for middle-aged subjects, but absolute excess risk was greater. Older people and middle-aged women with elevated cholesterol levels are clearly at increased risk of coronary disease; whether this risk can be modified by dietary or drug therapy, and at what level intervention is appropriate, must not be determined.