Seasonal variation in larval populations of three species of mosquitoes, Anopheles maculipennis, An. claviger and Culex pipiens, common in the vicinity of Ankara, were studied. Populations of An. maculipennis and Cx. pipiens disappeared in larval habitats by December but An. claviger, overwintering as larvae remained until the middle of March. Animal footprints are densely populated and are preferred by Cx. pipiens and An. claviger over larger water bodies.