BACKGROUND Transfusion-transmitted leishmaniasis is an increasing problem in areas where visceral and cutaneous leishmaniases are endemic. METHODS This article reports a case of transfusion-transmitted fatal visceral leishmaniasis (VL) caused by Leishmania (Leishmania) mexicana in a 42-year-old male resident of northwestern Colombia who after developing a terminal renal failure due to lupus nephritis received a renal transplant and multiple transfusions. RESULTS Multiple intracellular Leishmania amastigotes were demonstrated in both renal biopsy and marrow aspirates. Cultures of the parasite were obtained in NNN medium and the identification of the species was done both by direct immunofluorescence and polymerase chain reaction-restriction fragment length polymorphism. CONCLUSIONS This is the first report of a VL case produced by L. (L.) mexicana in Colombia, which usually is a dermotropic species. Our report suggests that although leishmaniasis is transmitted by the bite of phlebotomine sand flies, Leishmania parasite may be transmitted by blood transfusion, complicating the clinical course of organ transplant and being fatal.