Leishmaniasis is found in natural foci of infection where both sand fly vectors and mammalian reservoirs of Leishmania are present.To report for the first time the presence of Leishmania (Leishmania) mexicana Biagi, 1953, in the village of San Matías, municipality of Gomez Plata, Department of Antioquia.The parasite was isolated from a patient with localized cutaneous leishmaniasis and was identified by the immunofluorescence technique using specific monoclonal antibodies against L. mexicana species and isoenzyme electrophoresis.The isoenzymatic profiles of the reference strains L. (L.) mexicana (MNCY/BZ/62/M379) and L. (L.) mexicana (MHOM/BE/82/BEL21) were similar to that of the isolate recovered from the patient, allowing us to classify it as L. (L.) mexicana.