Gastric cancer is an aggressive malignancy, which, if metastatic or unresectable, is incurable. However, with metastatic or unresectable disease, patients receive a palliative benefit from chemotherapy. Although the understanding of the biology of this disease is increasing, the development of biologically targeted therapies for gastric cancer has been limited. Cytotoxic therapy remains the standard approach, and although there is agreement on the active agents and active combination chemotherapy regimens, consensus on the standard or reference regimen is lacking. This article reviews the pathophysiology of this disease, placing it in the context of its epidemiology, and the current advances in the treatment of this disease.