Background: The production of nitric oxide (NO) is important in the final outcome of leishmaniasis in animal models.Objective: The efficacy of garlic therapy and a combination of garlic and vitamin A were compared with an antimonial drug (glucantime) to assess healing and regulation of NO release in mice infected with Leishmania major.Methods: The mice were subjected to 3´105 promastigotes and allowed to induce a lesion. The mice were treated with above compounds twice a day for 45 days. The diameter of the lesion was measured on days 1, 10, 20, 30 and 45. In a separate experiment, NO release by peritoneal macrophages was measured.Results: The diameter of lesion was reduced by aqueous extract of garlic within 30 days of treatment. However, the maximum reduction was induced when mice were subjected to vitamin A for 10 days before the administration of the aqueous extract for 30 days. A significant correlation between healing and the amount of NO release was also found.Conclusion: A combination of aqueous extract of garlic and vitamin A can treat leishmanisis.