BACKGROUND Combined HMG-CoA reductase inhibitor and fibric acid derivative therapy is often necessary for the effective reduction of concentrations of low-density lipoprotein (LDL) cholesterol and triglycerides in patients with mixed hyperlipidemia; however, the potential risk of myopathy has limited the use of these agents. OBJECTIVE This study evaluated long-term safety and efficacy of combined pravastatin and gemfibrozil therapy. METHODS Eighty-three patients with hyperlipidemia were treated with combined pravastatin and gemfibrozil therapy for a median of 44 months (range 9-78 months). Plasma lipids, serum liver function tests, creatinine, and creatinine kinase (CK) levels were measured every 3 to 4 months. RESULTS One patient developed myalgia with a normal CK level after 4 months of combination therapy. Three patients had transient elevations in CK levels that ranged from 3 to 5 times the upper limits of "normal" and that returned to normal upon repeat testing. Liver function tests did not change significantly from baseline. In a subset of 26 previously untreated patients, combined pravastatin (mean daily dose 22 mg) and gemfibrozil (mean daily dose 1,154 mg) therapy lowered total cholesterol by 25% (p < 0.001), triglycerides by 53% (p = 0.0001), LDL cholesterol by 14% (p = 0.24), and increased high-density lipoprotein (HDL) cholesterol by 20% (p = 0.012). CONCLUSIONS Pravastatin and gemfibrozil therapy is safe and efficacious in patients with mixed hyperlipidemia. The long-term safety results are consistent with other reports on follow-up of shorter duration.