We report a case of primary non-Hodgkin lymphoma of the breast as third metachronous neoplasm in the same patient. Primary non-Hodgkin lymphoma of the breast occurred about 2 years after endometrial cancer and 1 year after bladder cancer. The patient underwent quadrantectomy with level I-II axillary lymph nodes dissection plus rituximab-cyclophosphamide, doxorubicin, vincristine, prednisone chemotherapy. Patient's health status gradually got worse and 11 months after surgery the patient died.