To determine their distributions, cholesterol and fasting triglycerides were measured in 10,991 black and white clerical workers. Among those workers solicited, 91% participated. Serum cholesterol level rose with age in both sex and race categories; there were no black/white differences for cholesterol. Cholesterol levels were similar between sexes until after the age of 50 when females had appreciably higher levels. In males, serum triglycerides rose sharply with age, peaking at the fifth decade and then falling. In females triglycerides rose with age. Within all age and race categories, whites had appreciably higher triglycerides than blacks and males higher than females.