To determine the effects of cigarette smoking on vaginal squamous epithelium in postmenopausal women, we studied the vaginal smear patterns of 199 healthy postmenopausal non-smokers and 41 healthy postmenopausal smokers, with a mean age of 56 years. A statistically significant difference to the hazard of smokers was found in the percentage of smears manifesting absence of maturation of vaginal squamous cells. A high incidence of atrophic-type vaginal smears in the group of smokers was also found independent of postmenopausal age. In the group of non-smokers, there was a statistically significant difference between the cytologic patterns of smears of women who were in the early postmenopausal age (<10 years) and those many years after (> or =10 years). Finally our data suggest that smokers had an earlier menopause, on average 2.4 years sooner than non-smokers. Cigarette smoking has an effect on vaginal squamous epithelium, but pathophysiology still remains unclarified.