The aim of this study was to study the effects of rosuvastatin in patients with rheumatoid arthritis (RA) looking at the C-reactive protein (CRP), interleukin-6 (IL-6) and joint disease activity. Fifty RA patients were randomized in a double-blind placebo-controlled trial to receive either 10 mg of rosuvastatin or placebo as an adjunct to existing disease-modifying antirheumatic therapy. Patients were followed up for a six-month period. Measurements were done at baseline and six months. CRP and IL-6 were measured in the blood. RA disease activity was measured using disease activity score based on 28 joint counts (DAS 28). When analysing from baseline to six months there was no difference between the rosuvastatin and placebo groups in rheumatoid disease activity (-0.01; standard deviation [SD], 1.08; and +0.18; SD, 0.95; respectively; P value 0.509). There was a trend towards improvement in CRP in the rosuvastatin group (-3.23; SD, 18.18) compared with the placebo group (+17.43; SD, 38.03); P value, 0.161. IL-6 showed a trend towards worsening in the rosuvastatin group (+0.15; SD, 1.09) compared with placebo (-0.73; SD, 1.4); P value, 0.054. These data show that rosuvastatin with might decrease the CRP independent to IL-6 in patients with RA but does not improve the overall rheumatoid disease activity.