Primary malignant breast lymphoma (PBL) is a rare disease with an incidence of 0.04-0.5% of all malignant breast neoplasms. The majority of cases are B-cell lymphomas and the most common histologic type is diffuse large B-cell lymphoma (DLCL). In this study, we report our experience with three cases of PBL. The treatment was the same currently indicated for early stage aggressive NHL, i.e. anthracycline based chemotherapy followed by the involved field radiation therapy. Unfortunately, two patients underwent mastectomy to carry out correct diagnosis. The three patients are alive without any evidence of relapse after 24, 67 and 135 months of follow-up. Considering that aggressive NHL is very sensitive to chemotherapy, mastectomy should be avoided to preserve the quality of life of these patients, once surgery does not change the good prognosis of PBL.