Gastric Cancer epidemics have changed over recent decades, declining in incidence, shifting from distal to proximal location, transforming from intestinal to diffuse histology. Novel chemotherapeutic agents combined with modern surgical operations hardly changed overall disease related survival. This may be attributed to a substantial inherent geographical variation of disease genetics, but also to a failure to standardize and implement treatment protocols in clinical practice. To overcome these drawbacks in Greece and Cyprus, a Gastric Cancer Study Group under the auspices of the Hellenic Society of Medical Oncology (HeSMO) and Gastrointestinal Cancer Study Group (GIC-SG) merged their efforts to produce a consensus considering ethnic parameters of healthcare system and the international proposals as well. Utilizing structured meetings of experts, a consensus was reached. To achieve further consensus, statements were subjected to the Delphi methodology by invited multidisciplinary national and international experts. Sentences were considered of high or low consensus if they were voted by ≥ 80%, or < 80%, respectively; those obtaining a low consensus level after both voting rounds were rejected. Forty-five statements were developed and voted by 71 experts. The median rate of abstention per statement was 9.9% (range: 0-53.5%). At the end of the process, one statement was rejected, another revised, and all the remaining achieved a high consensus. Forty-four recommendations covering all aspects of the management of gastric cancer and concise treatment algorithms are proposed by the Hellenic and Cypriot Gastric Cancer Study Group. The importance of centralization, care by a multidisciplinary team, adherence to guidelines, and individualization are emphasized.