OBJECTIVE Estimation of mean and median age at menopause among Iranian women using a cumulative distribution by region. METHODS The number of 8194 women aged between 30 and 65+ who enrolled in National Health Survey in the year 2000 in Iran through cluster sampling were studied and according to their age and the onset of their menopause (12 month consecutive menstrual cessation), the pattern of age at natural menopause has been described using a cumulative distribution. RESULTS The median age of menopause has been calculated to be 49.9, 49.2, and 49.6 years in urban, rural, and total population, respectively. While the mean age at menopause in total population was 50.4 years (S.D.=4.3). As it has been shown, the median age of menopause in rural areas (49.2) is earlier than urban areas (49.9). This difference is statistically significant (95% CI: 1.00066, 1.03363). CONCLUSIONS There are different factors influencing age at natural menopause but there are not certain and homogenous results about those factors in different studies. Therefore, it is obvious that exploring these factors in different regions in Iran merit to be done.