Data on I30 women with invasive breast cancer, seen at our institution between April 1981 and November 1990, were retrospectively reviewed to assess the influence of age and menstrual status on the pattern and prognosis of their disease. Patients were mostly young (median age 40 years) and in 21 patients (16%) the diagnosis was established at the age of 30 years or younger. Eighty-six patients (66%) were under 50 and 82 patients (63%) were pre-menopausal. Premenopausal patients were more numerous than expected in stage 111 and less numerous in stage II. On the other hand, the differences between observed and expected values for both stage I and stage IV in the 2 menopausal groups were not significant. Compared with post-menopausal patients, pre-menopausal patients with 1-3 or > 3 positive lymph nodes were more numerous than expected. Differences between pre-menopausal and post-menopausal patients have persisted after categorizing patients into 2 age-groups with a cut-off point at 50 years. Comparable initial assessment and therapeutic modalities were offered to the 2 menopausal groups. A t the time of analysis (January, 1991) all patients had a complete follow-up. Over a median follow-up of 46 months, the overall median survival (kSE) was 85.7 (k4.4) months with a survival probability ( S E ) at 5 years of 62% (*5%). The proportional hazard model of Cox has identified advanced stage (stages 111 and IV) and involvement of lymph nodes as the only independent adverse predictors of survival with estimated hazard rates of 2.9 and 2.8, respectively. Unadjusted analysis, adjusted analysis and stratified survival functions failed to reveal any survival difference based on age or menstrual status. We conclude that, in a low-risk population and despite apparent baseline differences in demographic and disease characteristics between pre-menopausal and post-menopausal breast cancer patients, neither age nor menopausal status had a significant influence on survival. Our results should guide future cancer-care programs in Saudi Arabia.