Background: Leishmania is a pathogenic parasite which infects mononuclear cells in vertebrate hosts. Different strategies have been taken to develop immunity against Leishmania . DCs loaded with immunogenic antigen have resulted in different levels of Th1-type immune response and cytotoxic T lymphocytes (CTL) activity. Objective: To evaluate the potency of DCs primed with soluble Leishmania mexicana antigens (SLA) in developing CTL activity. Methods: DCs were loaded with SLA and injected to Balb/c mice. After two weeks the mice were sacrificed and their splenocytes were used as effector cells in a standard 4-hour cytotoxicity assay against DCs transfected with pcDNA3 containing L. mexicana gp63 gene. Results: Immunization of Balb/c mice with DCs loaded with SLA resulted in high levels of CTL activity against DCs transfected with pcDNA3 containing L. mexicana gp63 gene. Conclusions: The results indicate a high potency for DCs primed with Leishmania antigens in inducing CTL activity, which can be used for developing an immunogenic vaccine against Leishmania.