The lipid-modifying effects of statin therapy in hypercholesterolemic African-Americans have not been well characterized. This study compared the efficacy and safety of rosuvastatin and atorvastatin treatment for 6 weeks in hypercholesterolemic African-American adults. In the African American Rosuvastatin Investigation of Efficacy and Safety (ARIES) trial (4522US/0002), 774 adult African-Americans with low-density lipoprotein cholesterol > or = 160 and < or = 300 mg/dl and triglycerides < 400 mg/dl were randomized to receive open-label rosuvastatin 10 or 20 mg or atorvastatin 10 or 20 mg for 6 weeks. At week 6, significantly greater reductions in low-density lipoprotein cholesterol, total cholesterol, non-high-density lipoprotein cholesterol, and apolipoprotein B concentrations, as well as lipoprotein and apolipoprotein ratios, were seen with rosuvastatin versus milligram-equivalent atorvastatin doses (analysis of variance with Bonferroni-adjusted critical p < 0.017 for all comparisons). Rosuvastatin 10 mg also increased high-density lipoprotein cholesterol significantly more than atorvastatin 20 mg (p < 0.017). Although statistical comparisons were not performed, larger proportions of rosuvastatin-treated patients than atorvastatin-treated patients achieved National Cholesterol Education Program Adult Treatment Panel III low-density lipoprotein cholesterol goals. The median high-sensitivity C-reactive protein levels were significantly reduced statistically from baseline with rosuvastatin 20 mg and atorvastatin 20 mg among all patients and with rosuvastatin 10 and 20 mg and atorvastatin 20 mg in those patients with a baseline C-reactive protein level > 2.0 mg/L. The 2 study medications were well tolerated during the 6-week study period. In conclusion, rosuvastatin 10 and 20 mg improved the overall lipid profile of hypercholesterolemic African-Americans better than did milligram-equivalent doses of atorvastatin.