Background Primary non-Hodgkin lymphoma is an extremely rare entity, and this condition represents less than 0.5% of all malignant lesions involving the mammary gland. As such, there has been a paucity of relevant clinical data arising from Southeast Asia. Aims Our study aims to review the clinical presentation, diagnostic methods, treatment, and survival outcomes of all patients diagnosed with primary breast lymphoma in our institution between 2011 and 2017. Methods and results Patients who had histologically proven lymphoma involving the breast were identified from a prospectively collected database in a single institution between 2011 and 2017. All seven patients were female, with a median age of 65 years old, and had presented with unilateral large breast or axillary masses. All the histological diagnosis was achieved with adequate tissue diagnosis either through core, incisional, or excisional biopsy. Five patients had diffuse large B cell lymphoma, one had marginal zone lymphoma, and the other had follicular lymphoma. Based on Ann Arbor classification, one patient had stage 1, three had stage 2, one with stage 3, and two patients with stage 4 disease. Five patients had received standard CHOP regimen with rituximab. At the time of analysis, patients who had nondisseminated disease had a median survival of 57 months. The overall mean survival time for all seven patients was 47 months. With the standard systemic chemotherapy treatment regimen, the estimated 3-year overall survival was found to be 64%. Conclusion Primary breast lymphoma, though uncommon, may present in a similar manner as breast carcinomas, but the main treatment modality remains nonsurgical with systemic chemotherapy. Hence, it is prudent to obtain accurate histological diagnosis of primary breast lymphoma. In this study, our patients with nondisseminated breast lymphoma have demonstrated a fairly good survival outcome following chemotherapy.