The primary goal of therapy in the treatment of hyperlipidaemia is to reduce the plasma concentrations of known atherogenic lipoproteins thereby reducing or even reversing the flux of lipids from plasma into the arterial wall. A less common goal is to prevent the adverse sequellae of hyperchylomicronaemia in patients with severe hypertriglyceridaemia. The aetiologic factor(s) responsible for hyperlipidaemia in a given patient need to be clearly established and it is important not to overlook potentially treatable secondary disorders. Diet is the cornerstone of therapy in the treatment of hyperlipidaemia; the decision to begin drug therapy should be individualized and should be made only after an adequate trial of diet has failed to achieve satisfactory concentrations of plasma lipids and lipoproteins. In this review I will discuss the use of diet and drugs in the treatment of patients with hypercholesterolaemia due to increased plasma concentrations of low density lipoproteins, patients with combined hyperlipidaemia in which very low and low density lipoproteins are elevated and patients with severe hypertriglyceridaemia in which chylomicronaemia is present.