The development of the infection process during cutaneous leishmaniosis was traced in one midday gerbil (Meriones meridianus Pall). The gerbil fell ill with cutaneous leishmaniosis after the feeding of san flies of Phlebotomus papatasi and Ph. mongolensis on it. The incubation process of the disease was less than 23 days. Leishmaniosic process began at the base of the concha auriculae and caused the destruction of ear tissues. The complete recover set in 67 days after the infection. Thus, the insignificant duration of the disease does not allow leishmaniae to be preserved in midday gerbils from one season to another.