The efficacy of simvastatin, an inhibitor of HMG-CoA reductase, was evaluated in 14 nondiabetic hypercholesterolemic continuous ambulatory peritoneal dialysis (CAPD) patients with or without hypertriglyceridemia. Following a hypolipemic diet for 6 weeks, simvastatin was administered at a dose of 10 mg/day for 6 months. After 6 weeks on simvastatin, cholesterol was reduced by 22% (p < 0.001), triglycerides by 24% (p < 0.001), low-density lipoprotein (LDL) by 27% (p < 0.001), while high-density lipoprotein (HDL) increased by 18% (p < 0.005). These changes remained steady for 6 months. Apolipoprotein-B (Apo-B) was reduced by 17.8% (p < 0.0001), while Apo-A was stable. There were no liver function abnormalities observed. In 3 patients serum creatinine kinase (CK) was increased, and in 2 treatment was stopped. No new lens opacities or other side effects were detected. Simvastatin seems to be an effective and relatively well-tolerated drug for dyslipemias in CAPD.