Background: Several factors contribute to increase breast cancer risk including age, genes, childbearing history, menstrual history, use of hormone therapies and socioeconomic and physical environment. The study aimed to make a review of the articles published from 1970 to 2008 that discuss whether breastfeeding reduces the risk of breast cancer. The review used the Pubmed database and included 25 research articles which examined the relation between breastfeeding and breast cancer. Results from studies investigating lactation and breast cancer risk have been inconsistent. However most studies suggest that extended period of breastfeeding during women’s life time can reduce breast cancer. Although breastfeeding may be one factor that reduces a woman’s risk of breast cancer, it is certainly not the only factor determining her risk. Conclusions: Since breastfeeding is a modifiable risk factor all women should be encouraged to breastfeed their children in order to keep themselves, their children, health systems and societies healthy.