OBJECTIVES: The aim of this study is to investigate the economic burden of gastric cancer in Turkey by evaluating it in terms of direct and indirect costs. METHODS: Cost of illness methodology was used. After the annual direct and indirect costs per patient were determined, the total cost based on prevalence was found. For the direct costs, the patient's consultation to the hospital during the year, laboratory and imaging tests conducted during consultation, hospitalization and medical interventions, drugs and side effects and complications were evaluated. Indirect costs were calculated on three parameters as premature death, labor loss, early retirement and transportation costs to the hospital. In addition, labor costs and transportation and food expenses were taken into account as companion costs. RESULTS: The calculations were made according to the information obtained from the expert panel, medical expenditures were calculated in accordance with the repayment perspective. It has been detected that the annual average outpatient cost of gastric cancer patients is $ 429.86 per patient, screening and laboratory costs are $ 775.59, hospitalization and medical interventions costs are $ 1,837.18, medication and application costs are $ 4,751.98 and side effect and complication costs are $ 5,106.88. The cost of an average gastric cancer patient from the health care payer perspective was $ 12,901.49 annually. According to the expert panel, the indirect cost per patient was $ 157,907.3, while the companion cost was $ 3,217.7. There are a total of 8,865 patients in Turkey, according to Globocan data and Ministry of Health. Total direct costs are $ 114,377,573 and indirect costs are $ 1,024,529,360. The economic burden of total gastric cancer patients is $ 1,138,906,933. CONCLUSIONS: Gastric cancer is an important economic burden for our country. National policy is needed for prevention of disease, increasing awareness, early diagnosis, access to treatment.