Background and Aim: EpCAM, also known as cluster of differentiation 326 (CD326), is a glycosylated, type I trans-membrane molecule, it is overexpressed in several types of neoplasms such as colorectal cancer and breast cancer. It is primarily identified as one of cell adhesion molecules (CAMs). Recently, it is considered as an emerging marker for detection of cancer stem cells (CSCs)in various neoplasms. EpCAM is proved as a critical factor in carcinogenesis. Emerging evidences suggest that it may play an important role in tumor development and progression; also it is reported to be implicated in tumor invasion and metastasis. The aim of this review was to highlight the current knowledge on the structure and function of EpCAM focusing on some mechanisms that may be involved in cancer progression with emphasis on the clinical significance of EpCAM as a diagnostic and prognostic marker.Conclusion:EpCAM moleculeis a prognostic indicator referring to tumor progression, metastasis and relapse. Targeting EpCAM in therapeutic approaches may be a useful strategy for cancer treatment and prevention of metastasis and relapse