OBJECTIVE We examined the therapeutic strategies for treating mild gastrointestinal (GI) graft-versus-host disease (GVHD) using oral beclomethasone dipropionate (BDP) in 15 Japanese patients based on the donor source. The primary objective was to determine the efficacy and toxicity of oral BDP combined with/without low-dose prednisone (PSL). METHODS Oral BDP was administered with 1 mg/kg/d of PSL in patients undergoing bone marrow transplantation (BMT) or peripheral blood stem cell transplantation (PBSCT; n=11), and the dose of PSL was tapered off after 22 days. Oral BDP alone was administered in patients undergoing cord blood stem cell transplantation (CBSCT; n=4). The primary endpoint was the rate of treatment success on day 49, as measured according to the improvement or complete resolution of GI symptoms without additional treatment. The secondary endpoints included treatment-related toxicity according to the National Cancer Institute Common Toxicity Criteria version 3.0, the rate of treatment discontinuation due to toxicity, the rate of relapse of acute GVHD by day 100 and the incidence of bacterial, fungal or viral infection, including cytomegalovirus (CMV) antigenemia. RESULTS Treatment success was achieved in seven of the 11 (64%) patients undergoing BMT or PBSCT and in all four patients (100%) undergoing CBSCT. Subsequent adverse events included herpes zoster infection, catheter-associated sepsis and CMV enteritis; all affected patients responded well to treatment. CONCLUSION The use of a risk-stratified treatment strategy with oral BDP depending on the stem cell source is effective in patients with mild GI-GVHD.