Triglycerides make up the overwhelming proportion of dietary fat consumed in the United States and other industrialized nations. Triglyceride elevation is directly associated with relative weight and age in both sexes, oral contraceptive use in women, and the development of diabetes mellitus. Triglyceride elevations are a highly significant independent risk factor for coronary heart disease (CHD) in women. They appear to be important in men with low high-density lipoprotein (HDL) cholesterol (less than 40 ml/dl). Dangerously high levels of triglyceride are associated with a high total cholesterol/HDL cholesterol ratio, which is an excellent indicator of CHD risk in both sexes. Individuals with elevated triglycerides should be considered at risk for CHD unless the total cholesterol/HDL cholesterol ratio is under 3.5. In practice, however, only about 10% of individuals with elevated triglycerides prove to have such low total cholesterol/HDL cholesterol ratios.