Breast cancer is, by far, the most frequent cancer among women and many factors influence the physiological and pathological growth and development of the mammary gland. There is developing evidence that the hormone ghrelin, known for the growth hormone releasing effect and food intake modulator, could also play a role in the pathogenesis of breast cancer and may represent a new diagnostic marker and a potential therapeutic target. We performed a PubMed Database search of relevant studies and ten papers were included in our systematic review. Ghrelin axis seems to be definitely involved in the pathogenesis of breast cancer, although a precise role has not been yet established. In order to verify the precise role of ghrelin axis in breast cancer further studies with larger populations are necessary that should include the analysis of metabolic, genetic and environmental factors which are expected to influence the results.