Hypolipidaemic 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitor (statin) treatment reduces cardiovascular risk and is also associated with the reduction of C-reactive protein (CRP) concentrations. However, there is scant data concerning the relationship between CRP and lipid changes during statin treatment. We studied 60 hypercholesterolaemic coronary patients who participated in the Treat to Target (3T) study comparing atorvastatin and simvastatin. Serum lipids and CRP (with a sensitive method) were measured before treatment at baseline and after 12 months of statin treatment. Low-density lipoprotein (LDL) cholesterol was substantially decreased and high-density lipoprotein (HDL) cholesterol increased during statin treatment. CRP decreased significantly (sign test P = 0.03) during treatment, and the changes of CRP were significantly associated with changes in HDL cholesterol (r = -0.45; P < 0.001) and apolipoprotein A1 (r = -0.40; P < 0.001) but not with changes in LDL cholesterol or triglycerides. The change in HDL cholesterol explained 20% of the change in CRP during statin treatment. The results are in line with previous suggestions that HDL has anti-inflammatory properties.