The efficacy of an antimony regimen at the dose of 20 mg/kg/day for a 3-4-week period is well established in the treatment of American cutaneous leishmaniasis. Several drug side effects, however, have been described and the search for more suitable regimens is advisable. In the present paper, the effect of a low dose (5 mg/kg/day for 30 days) of antimony was evaluated in 159 individuals from endemic regions of Rio de Janeiro State, Brazil, an area of Leishmania (V.) braziliensis transmission. Patients presented typical cutaneous lesions and parasites were demonstrated in all cases. One hundred forty-three patients were available for evaluation and of these, 120 (84%) were cured by the end of therapy. Twenty-three patients (16%) were considered treatment failures. Side effects were observed in only six patients (4%). Extensive follow-up (up to 10 years) disclosed no relapses or mucosal lesions. The results show that a low dose of antimony is less toxic, more appropriate, especially in children and elderly people, and has the same final result as that obtained with larger doses.