Effects of volatile components of the urine (VCU) of mature male and female CBA/LacStoRap mice on proliferating bone marrow cells in young females of the same line were analyzed. To estimate the effects of VCU, cytogenetic analysis of mitotic disturbances in anaphase-telophase cells was performed. The overall frequency of mitotic disturbances such as chromosome bridges, fragments, retarded chromosomes, and multiple rearrangements was assessed. The overall frequency of mitotic disturbances in young female mice treated with VCU from mature females for 2 h significantly increased 24 h after exposure. The spectrum of mitotic disturbances was also affected by the VCU treatment. After exposure to VCU from mature males, no significant variation of parameters analyzed was detected in young female mice. The possible mechanisms and role of specific effects of VCU from animals of different sexes on young female house mice are discussed.