ObjectiveTo review the application of omega-3 polyunsaturated fatty acids (Ω-3PUFAs) in patients with gastric cancer.MethodThe related literatures about the application of Ω-3PUFAs in patients with gastric cancer were reviewed by searching domestic and international databases.ResultsΩ-3PUFAs didn’t only improve the perioperative immune function and inflammatory response in patients with gastric cancer, but also prevent the occurrence of gastric cancer, inhibit the proliferation and promote the apoptosis of gastric cancer cells, increase the sensitivity of chemotherapy, and reduce the occurrence of chemotherapy-related adverse events.ConclusionsΩ-3PUFAsis an immunological nutrition, which can provide energy and also has functions of anti-inflammatory, anti-cancer, immunity regulation. It has been widely used in patients with gastric cancer, but the relevant mechanism needs further to be investigated.