Hypertriglyceridemia, diabetes, and coronary vessel disease are often interdependent disorders. Hyperglyceridemia may be exogenous, endogenous, or mixed. It may be familial or secondary to a host of different disorders. The clinical and chemical differentiation of hyperglyceridemia is discussed as are the roles of glucose intolerance, insulin response, dietary carbohydrate and fat, and obesity in each type of hyperglyceridemia. Specific therapeutic approaches which are designed to ameliorate at least the chemical manifestations of these disorders are reviewed.