Thirty-eight renal allograft recipients who had persistent hyperlipidemia and stable renal function 27.8 +/- 18.2 months after renal transplantation were treated with gemfibrozil. Gemfibrozil therapy resulted in a decrease in the levels of total cholesterol (TC; 297.6 +/- 41.0 mg/dl to 249.2 +/- 43.7 mg/dl, -16.3%; p < 0.0001), triglyceride (TG; 231.9 +/- 116.8 to 125.7 +/- 58.4 mg/dl, -45.8%, p < 0.0005), and LDL-cholesterol (LDL-C; 203.8 +/- 37.4 to 174.5 +/- 42.5 mg/dl, -14.4%; p = 0.001), which were sustained for 29.1 +/- 16.0 months. Comparison of sequential lipid profiles between gemfibrozil-treated individuals and untreated hyperlipidemic controls matched for age, sex, time after transplantation, and the degree of hyperlipidemia, showed that gemfibrozil-treated patients had lower levels of TC (239.9 +/- 39.5 vs. 272.8 +/- 34.1 mg/dl; p < 0.005), TG (125.7 +/- 26.6 vs. 167.3 +/- 69.0 mg/dl; p < 0.05), and LDL-C (160.2 +/- 41.3 vs. 185.3 +/- 26.6 mg/dl; p < 0.05) on serial follow-up. No significant side-effect was observed with gemfibrozil therapy. Our data showed that gemfibrozil was a safe and effective drug for the treatment of hyperlipidemia in renal allograft recipients, which could reduce these patients's long-term cardiovascular risks.