Abstract: Tegumentary leishmaniasis is a disease caused by a protozoan parasite belonging to the genus Leishmania. This disease can occur by four different forms: localized cutaneous, disseminated cutaneous, mucocutaneous or diffuse cutaneous. In Brazil, tegumentary leishmaniasis is caused mainly by the following species of the parasite: Leishmania (Viannia) braziliensis, L. (V.) guyanensis and L. (Leishmania) amazonensis, being the former one the most prevalent species. The virus LRV1 are double-stranded RNA virus found in species of Viannia subgenus, mainly L. (V.) braziliensis and L. (V.) guyanensis. Recent studies, in endemic areas in South America, have shown that there is a correlation between clinical treatment failure and the presence of Leishmania LRV1 virus in clinical isolates from patients. In this project, our objective is to evaluate the presence of LRV1 virus in 11 isolates of patients with tegumentary leishmaniasis of Instituto de Infectologia Emílio Ribas, São Paulo, SP Ver menos