In the Balearic Islands, as in other areas in southern Europe, there are a significant proportion of asymptomatic Leishmania infantum-infected blood donors. Theoretically, these donors may represent an important challenge for blood transfusion safety. However, despite an active search of multiply transfused patients, there have been, so far, no cases of transfusion-transmitted leishmaniasis (TTL) in our region. On the other hand, there is scarce evidence of the TTL in the literature. A review of asymptomatic Leishmania-infected blood donors' studies in endemic areas and TTL reports published in the English literature were performed, to ascertain the factors that determine the real risk of transfusion transmission of Leishmania.