Breast cancer is the leading women's cancer worldwide. However, there are geographical considerable differences with high rates of disease in North America and North Europe and relatively low rates in Africa and Asia. This article reviews the effects of reproductive factors on risk of breast cancer: early menarche, nulliparity or late age at first birth, late menopause, as well as hormonal factors. Knowing risk factors of breast cancer could significantly contribute to an improved prevention of this cancer. Furthermore, this review aimed to highlight potentially controversial conditions in the Asian countries compared to other parts of the world which could in the future improve early prevention of breast cancer in Asian women.