The aim of our study was the investigation of menstrual function in 102 women whose children suffer from acute lymphoblastic leukemia (ALL). The study was done by the method of “case — control” including the date of first menses, the regularity of menstrual function duration of cycle, volume of menses. There were 102 women in a control group all of which had healthy children. We determined that menstrual function disorders in mothers with children suffering from ALL happens much more often than in mothers with healthy kids. Mothers of children suffering from ALL had late begining of menses (15 years old or older), shortened (up to 2 days) or prolonged menses. The received data is veiwed from the point of possible negative role of genetical defects of program control of genome stability on the process of maturation of sex cells.