Background: Gastric cancer is one of the gastrointestinal tract cancers with the highest mortality rate; hence, accurate knowledge of the main causes of this disease is of paramount importance to plan, monitor, and evaluate national and regional programs to control this cancer. The present study was to rank and prioritize gastric cancer risk factors. Methods: In this study, gastric cancer risk factors were first extracted in a systematic review, and they were then ranked and prioritized using a focused group discussion. MICMAC software was used to rank the factors. Results: According to the findings, the following 13 factors had the highest effect on the incidence of gastric cancer: socioeconomic status, age, consumption of pickles and sour vegetables, salt consumption, meat consumption (red, smoked, and processed and salty), consumption of fried foods, consumption of fats and oils, consumption of fish (Salty, smoked, and processed), consumption of bread and leftovers and moldy foods, irregular eating habits, excessive daily calorie intake, smoking (cigarettes, opium, and hookah), and alcohol consumption. Conclusion: Prioritizing risk factors would help policymakers identify and present executive strategies and detect action priorities to manage gastric cancer risk factors. According to the findings of the present study, national planning to support vulnerable socio-economic groups, the development of screening programs, and the early detection of diseases in the early stages at an early age, and diet adjustment to increase the consumption of fresh fruits and vegetables and reduce salt, high-fat and fried foods, salted foods, and processed meats are recommended.