We conducted a randomized, controlled study in southern Colombia to determine if the addition of allopurinol to stibogluconate was superior to stibogluconate alone in the treatment of cutaneous leishmaniasis. Lesions that healed after a 3-month course of therapy and remained so during a 1-year period of follow-up were considered cured. The cure rate for patients treated with stibogluconate was 39%; the addition of allopurinol increased this rate to 71% (P = .005). For the treatment of cutaneous leishmaniasis, the combination of allopurinol and stibogluconate is significantly more effective than is stibogluconate alone. These results support those of other clinical studies in which allopurinol and stibogluconate were shown to be superior to stibogluconate alone. The aggregate data support the use of allopurinol as an inexpensive, orally administered agent that can be used as an adjunct to stibogluconate or, perhaps, other oral agents in the treatment of cutaneous leishmaniasis.