The microscopic study of the dermal smears of 62 cases of cutaneous leishmaniose, 27 infected by Leishmania (L.) infantum and 35 by L. major, showed that the amastigotes of L. infantum are meaningfully smaller (p < 0.001). This criteria is a simple pary alternative to distinguish these 2 species which have completely different epidemiology, recovery delay and prophylactic dispositions.