Chronic pruritic skin lesions are considered to be one of the late complications of sulfur mustard exposure. The purpose of this study was to compare the efficacy of topical capsaicin with that of betamethasone in the treatment of these lesions. In this investigator-blinded, randomized clinical trial, patients applied capsaicin cream 0.025% (n=32) or betamethasone cream 0.1% (n=32) 2 times a day for 6 weeks. Efficacy was based on a dermatologist assessment. The severity of the pruritus was assessed by pruritic score questionnaire and a visual analog scale before and after treatment. All patients complained of pruritus. Both groups showed a significant decrease in pruritus, scaling, and skin dryness (p<0.05), but burning sensation was not improved significantly in the capsaicin group. The mean (+/- standard deviation [SD]) baseline pruritic scores in the capsaicin and betamethasone groups were 29.4 (13.1) and 33.6 (7.2), respectively (p=0.1). The mean (SD) pruritus score change from baseline to after the treatment was significantly higher (p<0.001) in the betamethasone group than in the capsaicin group, 12.7 (6.4) vs. 6.9 (5.6). Fourteen (35%) patients in the capsaicin group reported a burning sensation and intolerable odor, but these effects were not serious enough to necessitate discontinuing the treatment. Topical capsaicin cream 0.025% was much less well tolerated than betamethasone and inferior to betamethasone in reducing chronic skin lesions and symptoms from sulfur mustard exposure.