Nicotinic acid is an effective agent for elevating HDL cholesterol but is limited by side effects. In order to improve tolerance and lipid levels, we combined low-dose nicotinic acid with bezafibrate. We gave low-dose (mean 435 mg/day) nicotinic acid to 37 patients with low HDL cholesterol, bezafibrate (mean 476 mg/day) to 58 patients with elevated total cholesterol and both agents (mean nicotinic acid 435 mg/day and bezafibrate 512 mg/day) to 25 patients with low HDL cholesterol and elevated total cholesterol. A total of 53 additional patients were followed as controls. Three intervals of treatment were studied: 0-6, 6-12 and > 12 months. The combination of drugs resulted in significant (P < 0.05) percentage changes in total cholesterol, triglycerides and total/HDL cholesterol compared to nicotinic acid alone and significant (P < 0.04) percentage changes in HDL cholesterol compared to bezafibrate alone. It is concluded that low doses of nicotinic acid may result in significant changes in HDL cholesterol; when combined with bezafibrate significant alterations in total cholesterol, triglycerides and total/HDL cholesterol also result.