600 mg of bezafibrate daily were administered to 13 well controlled diabetics with hyperlipidaemia for 12 weeks. Placebo was given before and after the treatment period. Compared with pretreatment placebo, bezafibrate reduced triglycerides (between 37 and 47%) and cholesterol (between 12 and 19%) significantly. Blood glucose levels during treatment were significantly lower at 8 and 12 weeks compared with post-treatment placebo values. Urinary glucose excretion did not change. Hypoglycaemia was not observed. No change in antidiabetic medication was necessary. Bezafibrate was well tolerated. It lowered blood lipids effectively in diabetics with hyperlipidaemia. No additional precautions have to be taken to control carbohydrate metabolism during bezafibrate treatment.