Breast cancer is the most common female cancer and the second most common cause of cancer death in women. Many risk factors have been associated with breast cancer. These can be grouped into categories including factors related to demographics (eg, age, ethnicity/race); reproductive history (age at menarche, parity, age at first live birth, age at menopause); familial/genetic factors (family history, known or suspected BRCA 1/2, p53, PTEN or other gene mutation associated with breast cancer risk); environmental factors (prior thoracic irradiation before age 30 [eg, to treat Hodgkin’s disease], hormone replacement therapy, alcohol consumption); and other factors (eg, number of breast biopsies, atypical hyperplasia or lobular carcinoma in situ [LCIS], breast density, body mass index [BMI]). Estimating breast cancer risk for the individual women is difficult. The development of effective strategies for the reduction of breast cancer incidence has also been difficult because of the few of the existing risk factors are modifiable. A number of lifestyle changes may reduce breast cancer risk. Even if breast cancer incidence cannot be substantially reduced for some women who are at high risk for developing the disease, the risk of death from breast cancer can be reduced by regular mammography screening. For women who are already at higher than average risk, their risk of developing breast cancer can be reduced by at least 50 percent or more by taking tamoxifen or raloxifene for five years. Risk reduction surgery is another option for high risk patients and should be considered after multidisiplinary consultations.