Cancer is one of the most fatal diseases in human beings which annually leads to death of 30000 individuals in Iran. Prevention, diagnosis and treatment of cancer is one of the major scientific challenges all around the world. It seems that increased incidence of several cancers such as colon and prostate and their mortality are connected with obesity. It is suggested that obesity and metabolic syndrome are associated with endocrine related cancers and ghrelin pathway may play a role in cancer progression. Ghrelin is a potent regulator of the growth hormone (GH)/ insulin-like growth factor-1 (IGF-1) axis, which is frequently implicated in the development of several neoplasms, including colon cancer. It has been reported that changed ghrelin level as a main regulator of energy homeostasis plays an important role in carcinogenesis. Also, antiproliferative effects of ghrelin in lung and breast carcinoma cell lines have been detected in some studies . In this paper, ghrelin and its role and function in cancer is discussed.