This study aimed to evaluate the long-term prognosis of patients with gastric mucosa-associated lymphoid tissue (MALT) lymphoma, including overall survival (OS), remission, and factors associated with an aggressive disease course. Medical records of 153 patients diagnosed with gastric MALT lymphoma between 2013 and 2020 were retrospectively reviewed. Patients experiencing relapse, progression, high-grade transformation, or residual diseasewere included in the aggressive group and were compared with those in the indolent group. Additionally, the endoscopic findings of Helicobacter pylori-negative patients were reviewed. Patient characteristics were as follows: mean age (56.9±11.2 years), sex (male, 51.0%), H. pylori infection (positive, 79.7%), endoscopic location (distal, 89.5%), endoscopic feature (superficial, 89.5%), clinical stage (stage I, 92.8%), invasion depth by endoscopic ultrasound (mucosa, n=115, 75.7%), and bone marrow result (no involvement, n=77, 100.0%). The median follow-up period was 59 months (mean, 61; range, 36-124) and the continuous remission period (n=149) was 51 months (mean, 50; range, 3-112). The 5-year survival rate was 97.7% while the 5-year continuous remission was 88.3%. Factors associated with the patients in the aggressive group were old age, sex(male), and clinical stage II or higher. H. pylori-negative patients' endoscopy revealed a high incidence of atrophic gastritis in the antrum. The long-term prognosis of gastric MALT lymphoma appears indolent and is indicated by the 5-year OS and continuous remission rates. Aggressive disease courses are associated with old age, sex (male), and clinical stage II or higher, but are not related to OS.