Healthy women and women with breast cancer have been enrolled in our nested case-control study between 2008 and 2009 in order to evaluate the association between metabolic syndrome and breast cancer, analyzing anthropometric parameters blood pressure, assessing serum HDL-C, triglyceride, fasting plasma glucose, insulin, testosterone and uric acid levels and administering a questionnaire about physical activity, food intake, tobacco use, alcohol abuse, personal and familial history of disease. Our data support the hypothesis that metabolic syndrome may be an indicator of breast cancer risk in postmenopausal women. The change of the hormonal arrangement in postmenopausal, along with an increase in visceral adiposity, probably favour the hormone dependent cell proliferation, which drives tumorigenesis. Adjustments in lifestyle with physical activity intensification and healthy diet may represent modifiable factors on which sporadic breast cancer primary prevention may work on.