Background: Globally, one million women are diagnosed with breast cancer and nearly half million die because of it. Breast cancer is one of the most common cancer which leads to mortality among women. Objectives: The main aim of this research is to find the relationship of prolactin level in women with breast cancer. Methods: The research was conducted in the Al-Hussein Medical City at Al-Hussein Center for the treatment of tumors and blood diseases. A total of 71 specimens were collected from females with breast cancer. Blood specimens were collected, and a blood group, PCV, Hb, ESR and prolactin level was evaluated. Results: The results show that most breast cancer cases were in age group 40-50 years, and less common among other age groups. The married women were 97% and the unmarried was 3% only. Most studied cases (43%) were O +ve and 26% were A +ve blood group, in comparison to other blood groups. Also, many women show a slightly decrease in hemoglobin and PCV level (<11.0 g/dl, <36% respectively), on the other hand the mean value of ESR was increased non-significantly (p>0.05). The prolactin levels were increased (31.5 ng/ml) significantly in compare to normal range (2-27 ng/ml) in women in all age groups. Conclusion: The study concludes that there was a relationship between prolactin level and breast cancer with a highly significant value.