Basiliximab is a chimeric monoclonal antibody that binds to the α chain of IL-2R on activated cytotoxic T-cells, inhibiting lymphocyte proliferation. We report 34 patients with refractory acute GVHD (grade III-IV) who received basiliximab from December 1998 to October 2003. Adults received 40 mg weekly (2-3 doses) and children received half of this dose. Median age was 13 years. Twenty-five donors were unrelated. The stem cell source was bone marrow in 30 and cord blood in four. Complete responses were seen in 27/32 patients (84%) with skin, 12/25 (48%) with gut and 6/23 (26%) with liver GVHD. Median duration of response was 38 days (5-1103). Overall survival at 5 years was 20%. Eleven patients (32%) are alive. The main causes of death were CMV (n = 4), fungus (n = 6), sepsis (n = 8), hemorrhage (n = 2), and relapse (n = 2). Graft-versus-host disease flares were observed in 14 patients (41%), half being rescued by other therapies. In conclusion, basiliximab was able to induce complete responses in patients with refractory acute GVHD. Prospective studies are necessary to evaluate the optimal treatment schedule.