We report the results of a retrospective analysis in 27 pediatric patients who received low-dose MTX as the second-line treatment for steroid-refractory or -dependent acute and chronic GVHD. Between July 2000 and May 2006, 10 patients with aGVHD and 17 with cGVHD were treated with MTX at a dose of 3-10 mg/m(2) weekly. Seven of ten patients (70%) with aGVHD responded well to MTX, thus resulting in the achievement of either a complete response (CR) or a partial response (PR). The dose of prednisone could be reduced to equal to or lower than 1 mg/kg in the responding patients at the end of MTX therapy. The median number of MTX administrations was five (range, 1-7). Ten (58.8%) of seventeen patients with cGVHD achieved CR or PR. The dose of prednisone could be reduced to lower than 0.4 mg/kg in 16 of 17 patients and seven patients could discontinue prednisone. The median duration of MTX administration was 18 months (range, 1-68). The toxicities of grade III to IV occurred in only six patients presenting cytopenias or elevated levels of serum transaminases. Low-dose MTX was tolerable and effective for the steroid-refractory or -dependent GVHD in reducing the dose of steroid without increasing the risk of opportunistic infection.