Common voles (Microtus subarvalis) were infected with tularemia by feeding them with the corpses of the animals which had been infected with Francisella tularensis strain having somewhat decreased virulence. This resulted in nonlethal infection in 14 out of 433 voles used in the experiment. A considerable part of the animals having had the infection developed bacterial carriership (11 out of 13 animals) with bacteriuria (8 out of 11 animals) lasting up to 2 months. The persistence of Francisella tularensis in the body of the animals having had the infection could last as long as 6-11 months. The possible epizootological importance of the latent course of tularemia infection in common voles is discussed.