Mycophenolate mofetil (MMF) has recently been reported as a useful alternative immunosuppressive drug in autoimmune diseases including in Takayasu arteritis (TA). The aim of this study was to verify the efficacy and tolerability of MMF administration in controlling TA disease activity and allowing glucocorticosteroid reduction. Ten consecutive active TA patients followed at the Vasculitis Clinic were enrolled from January 2003 to 2006 and received oral MMF (2 g/day) for an average of 23.3 months. Disease activity assessed using the National Institutes of Health criteria, clinical features, and inflammatory laboratory findings were evaluated. Five patients had received at least one immunosuppressive drug before administration of MMF (four methotrexate, two azathioprine, and one chlorambucil) but had not achieved clinical and laboratory remission. The other five patients received MMF as their first immunosuppressive drug because of an important disease flare during steroid dose reduction. Clinical activity disappeared in all patients with MMF therapy, except in one patient who abandoned the study because of an important headache, attributed to the drug. Moreover, the MMF therapy allowed significant tapering of the prednisone dose in the rest of the nine patients (24.5 +/- 17.1 vs 5.8 +/- 7.8 mg/day; p = 0.0019). Reinforcing this finding, a significant reduction in inflammatory laboratory parameters, erythrocyte sedimentation rate (24.7 +/- 15.5 vs 12.8 +/- 10.8 mm/h; p = 0.036) and C-reactive protein (24.0 +/- 14.9 vs 11.2 +/- 10.7 mg/l; p = 0.0167), was observed. In summary, MMF therapy reduced clinical and laboratory parameters of TA disease activity, suggesting that this drug is a promising immunosuppressive drug, particularly in refractory cases and as a steroid-sparing agent.