Aim To study the short-term effect of atorvastatin on C-reactive protein (CRP) in patients with or at risk for coronary heart disease. Methods and Results One hundred and fifty-five randomly selected patients from the SWiss Intervention Trial for lowering CHolesterol (SWITCH) were assessed for high sensitivity CRP, total cholesterol, LDL-cholesterol, HDLcholesterol and triglycerides at baseline, and after I and 3 months of treatment with atorvastatin at various doses to reach pre-defined lipid target values. The median decrease of cholesterol was 28% after 1 month and 35% after 3 months. LDL-cholesterol was decreased by 37% and 45%, HDL-cholesterol was increased by 7% and 8%, respectively. Patients with a low CRP baseline concentration (lowest quartile < 1.34 mg.l(-1)) displayed no significant change, whereas patients in the other quartiles showed a significant decrease, of 22% to 40% (P-value <0.05 to <0.001) at I month and of 32% to 36% after 3 months compared to baseline. The decrease in CRP lowering was thus fully 0 established by 1 month and this respons, was independent of lipid and lipoprotein changes as well as atorvastatin doses. Conclusion Atorvastatin significantly decreases CRP concentrations after 4 weeks of therapy. These results may be important with respect to the early benefit of statin therapy. (C) 2001 The European Society of Cardiology. Published by Elsevier Science Ltd. All rights reserved.