The objective of this study is to analyze the clinical characteristics and treatment of patients with primary non-Hodgkin's lymphoma of the breast (PNHLB). Forty-five patients with PNHLB treated in our hospital during a 15-year period were retrospectively analyzed. Forty-four were females and one male, with a median age of 47 years. Forty-two patients were at stage I or II and 82.2% had diffuse large B cell lymphoma (DLBCL). Local control rate was 95.2 and 66.7% for patients with and without radiotherapy, respectively (P = 0.020). Median overall survival and progression-free survival (PFS) of all patients was 6.8 and 4.3 years, respectively. For patients with DLBCL or T cell lymphoma, median PFS was 6.5 years with chemoradiation and 3.9 years with chemotherapy or radiation only (P = 0.029). Patients who used rituximab had not reached median PFS, while those treated without rituximab had a median PFS of 5.1 years (P = 0.301). International prognostic index (IPI) score and bilateral breast involvement were two independent prognostic factors for survival. Chinese patients with PNHLB have early occurrence in lifespan. Radiation confers a better local control. Patients with intermediate or high-grade PNHLB might be treated with chemotherapy, radiotherapy, and for CD-20 positive disease, rituximab. Bilateral disease and IPI are two prognostic factors.