Breast cancer is the most common cancer among women and a major public health problem in industrialized countries. Only 5-10% of breast cancer is attributable to genetic susceptibility. Most cases of this disease are probably related to lifestyle or environmental factors. It is difficult to define which factors exactly affect the risk of breast cancer. The aim of this work was to analyze the relationship between selected factors including diet, physical activity and breast cancer risk. According to some scientific investigations, proper diet and regular physical activity may decrease risk of death from this cancer. It is estimated that more than 50% of breast cancer cases could have been prevented if our current knowledge of risk factors were successfully implemented to reduce risk factors prevalence. It can be achieved by elaborating effective educational and early diagnostic programs.