Despite the availability of various lipid lowering drugs, the treatment of hyperlipidemia, one of the most important risk factors for morbidity and mortality after organ transplantation, remains a therapeutic challenge. We investigated the safety and efficacy of a new HMG-CoA reductase inhibitor, atorvastatin, in renal transplant patients whose serum lipids were insufficiently controlled by diet and treatment with other lipid lowering drugs. Twenty-four patients (14 males/10 females; mean age 51.2 +/- 2.3 years) were converted to low dose atorvastatin (10 mg/day) at a mean of 67.7 +/- 8.6 months after renal transplantation and prospectively followed for 3 months after initiation of the study drug. HDL, LDL, and total cholesterol, triglycerides, serum creatinine and CPK levels were evaluated pre (-3, -1, 0 months) and post conversion (+1, +3 months). In the eighteen patients who completed the study, low dose atorvastatin therapy led to a significant reduction in total cholesterol (304.6 +/- 13.2 vs. 247.6 +/- 12.0 mg/dl; p = 0.007) and LDL cholesterol (191.9 +/- 9.0 vs. 141.8 +/- 14.7 mg/dl; p < 0.0001) and a modest reduction in serum triglyceride levels at three months after conversion. We conclude that low dose atorvastatin (10 mg/day) can be successfully used and appears to be safe in the treatment of posttransplant hyperlipidemia. Its long-term effects on patient morbidity and mortality as well as graft survival should be investigated in larger and more prolonged prospective trials.