Lipid abnormalities are seen frequently in renal transplant patients. Cardiovascular disease is an important cause of morbidity and mortality in these patients. We assessed the efficacy and safety of the lipid-lowering drugs, nicotinic acid (short acting) and lovastatin, the 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor. Twelve renal transplant patients who had persistent hyperlipidemia despite 6 weeks of dietary treatment participated in this prospective, randomized, open-labeled crossover trial. At 16 weeks, when compared with control values, nicotinic acid (≥ 1.5 g twice a day) significantly reduced the total cholesterol (from 312 ± 18 [±SEM] mg/dL to 229 ± 19 mg/dL; P = 0.03) and the low-density lipoprotein cholesterol (from 218 ± 15 mg/dL to 142 ± 13 mg/dL; P = 0.03) and significantly increased the high-density lipoprotein cholesterol (from 44 ± 3 mg/dL to 58 ± 5 mg/dL; P = 0.03). The triglyceride level was reduced from 255 ± 40 mg/dL to 150 ± 23 mg/dL (P = 0.09). At 16 weeks, lovastatin therapy (40 mg/d) significantly reduced the total cholesterol (from 285 ± 13 mg/dL to 233 ± 10 mg/dL; P = 0.005) and the low-density lipoprotein cholesterol (from 201 ± 11 mg/dL to 147 ± 7 mg/dL; P = 0.001). There were no significant changes in the triglyceride and high-density lipoprotein cholesterol levels. Although flushing developed in 67% of patients treated with nicotinic acid, this was not a reason for any of the study dropouts. During this short-term study period no adverse biochemical effects were noted with either of the drugs. These findings indicate that both nicotinic acid and lovastatin reduce the total and low-density lipoprotein cholesterol levels. In addition, nicotinic acid significantly alters the triglyceride and high-density lipoprotein cholesterol levels. Nicotinic acid is an effective and inexpensive lipid-lowering agent in patients who tolerate the drug. Therapy with nicotinic acid could potentially reduce the risk of cardiovascular events in this group of high-risk patients.