Primary non-Hodgkin's lymphomas (NHL) of the breast represent less than 3% of extranodal NHL; in comparison to extranodal NHL at other sites, they are characterized by rapid progression and worse prognosis. We report a case of primary NHL of the breast treated, after surgery, with a sequential combination of chemotherapy and radiotherapy. Literature data suggest that the most important factors in therapeutic decisions making are the initial stage of the disease and the histological subtype.