This randomized, double-blind, placebo-controlled trial was conducted in 52 centers in North America to compare the effects of the new, highly effective statin, rosuvastatin, with atorvastatin and placebo in hypercholesterolemic patients. After a 6-week dietary run-in, 516 patients with low-density lipoprotein (LDL) cholesterol > or =4.14 mmol/L (160 mg/dl) and < 6.47 mmol/L (250 mg/dl) and triglycerides < or =4.52 mmol/L (400 mg/dl) were randomized to 12 weeks of once-daily placebo (n = 132), rosuvastatin 5 mg (n = 128), rosuvastatin 10 mg (n = 129), or atorvastatin 10 mg (n = 127). The primary efficacy end point was percent change in LDL cholesterol. Secondary efficacy variables were achievement of National Cholesterol Education Program (NCEP) Adult Treatment Panel II (ATP II), ATP III, and European Atherosclerosis Society LDL cholesterol goals and percent change from baseline in high-density lipoprotein (HDL) cholesterol, total cholesterol, triglycerides, non-HDL cholesterol, apolipoprotein B, and apolipoprotein A-I. Rosuvastatin 5 and 10 mg compared with atorvastatin 10 mg were associated with greater LDL cholesterol reductions (-40% and -43% vs 35%; p <0.01 and p <0.001, respectively) and HDL cholesterol increases (13% and 12% vs 8%, p <0.01 and p <0.05, respectively). Total cholesterol and apolipoprotein B reductions and apolipoprotein A-I increases were also greater with rosuvastatin; triglyceride reductions were similar. Rosuvastatin 5 and 10 mg were associated with improved achievement in ATP II (84% in both rosuvastatin groups vs 73%) and ATP III (84% and 82% vs 72%) LDL cholesterol goals, and rosuvastatin 10 mg was more effective than atorvastatin in achieving European Atherosclerosis Society LDL cholesterol goals. Both treatments were well tolerated.