AIM: To investigate the clinical features, treatment and prognosis of primary ocular adnexal mucosa-associated lymphoid tissue lymphoma (POAML). METHODS: A retrospective analysis was performed on 64 patients with POAML who were admitted to the First Affiliated Hospital of Zhengzhou University from January 2006 to December 2018. RESULTS: With a median follow-up of 61mo (range, 2-156mo), estimated overall survival (OS) rate and progression-free survival (PFS) rate at 10y reached 94.5% and 61.5%, respectively. Median OS time and PFS time were not reached. During this period, only 3 patients died, but none of them died directly due to disease progression. One patient (1.6%) developed transformation to diffuse large B-cell lymphoma (DLBCL). Of the 56 patients achieved complete remission after first-line treatment, 5 (8.9%) developed local and/or systemic relapse eventually. Patients ≥60y had significantly shorter PFS than younger patients (P=0.01). For patients with early stages (Ann Arbor stage I and stage II), univariate analysis confirmed that radiotherapy dose lower than 32 Gy were independently associated with shorter PFS (P=0.04). Other factors including gender, bone marrow involvement, the initial location of the disease, and the laterality were not associated with PFS. CONCLUSION: The data from our center indicate that POAML has a slow clinical progression and has an excellent clinical outcome. Patients with POAML harbor a continual risk of relaps and transformation to aggressive subtype of lymphoma.