The ability of breast tumors to synthesize sex steroid hormones is well recognized and their local production is thought to play a role in breast cancer development and growth. The aim of this study was to estimate local intra-tumoral and circulating levels of Estrone (E1), Estrone Sulfate (E1S), Estradiol (E2), Estriol (E3), and Testosterone (T) in 33 pre- and postmenopausal women with primary breast cancer in comparison to 12 pre- and postmenopausal women with benign breast tumors. The mean levels of the studied sex hormones were higher in serum and tumor tissue of breast cancer women than those with benign breast tumors apart from Testosterone which showed a significant decrease in pre- and postmenopausal women with breast cancer (P<0.001for follicular phase, P<0.05 for luteal phase, and P<0.005 for postmenopausal). The levels of the five hormones were significantly higher intra-tumoral than in serum of both benign and malignant breast tumor women with E1S as the predominant estrogen. There was only a positive significant correlation between serum and tumor tissue levels of E1 (rs=0.52, P<0.05 for follicular; rs=0.63, P<0.05 for luteal and rs=0.58, P<0.05 for postmenopausal) and a significant correlation between serum and tumor tissue of T (rs=0.64, P<0.05 for follicular; rs=-0.51, P<0.05 for luteal and rs=-0.81, P<0.04 for postmenopausal).