We determined the efficacy of the combination of the topical formulation 15% paromomycin sulfate/12% methylbenzethonium chloride (MBCL) and a short course (7 days) of parenteral meglumine antimonate (pentavalent antimony [Sb]) as treatment of American cutaneous leishmaniasis in Colombian patients. Patients were randomly assigned in unequal allocation (2:1:1:1) to group 1 (topical paromomycin/MBCL plus injectable Sb for 7 days), group 2 (topical placebo plus injectable Sb for 7 days), group 3 (topical paromomycin/MBCL plus injectable Sb for 3 days), and group 4 (injectable Sb for 20 days). Cure was defined as complete reepithelialization of all lesions without relapse. Cure rates among groups were as follows: 58% (34 of 59), group 1; 53% (16 of 30), group 2; 20% (6 of 30), group 3; and 84% (26 of 31), group 4. Seventy-one percent of the organisms identified to the species level were Leishmania braziliensis panamensis. We conclude that 10 days of therapy with paromomycin/MBCL does not augment the response of cutaneous leishmaniasis (predominately due to L. braziliensis panamensis) to a short course of treatment with meglumine antimonate.