To answer whether the age-related accumulation of chromosomal damage differs in men and women, and whether the aberration level in centenarians is proportional to their age, cytogenetic aberrations in dividing cells were analyzed. G-band karyotyping of mitotic spreads from lymphocytes was performed in 52 Polish centenarians and 71 controls (aged 21-78). Statistical evaluation was performed using nonparametric tests and regression analysis. The average level of all chromosomal aberrations was comparable in centenarians of both genders, but the age-related increase in chromosomal damage occurred faster in women than in men. Aging in both genders was marked by the increasing level of all aberrations rather than by chromosome-specific changes; the loss of X chromosome was the leading contributor in women. The age-related increase in the level of chromosomal damage reflected accumulation of dividing cells with a small number of aberrations. Individuals who survive to the extreme old age appear to accumulate aberrations at the slower rate.