Primary nonHodgkin's lymphoma (NHL) occurs in both nodal and extranodal sites. Lymphoma arising in mammary tissue is rare. The majority are of B-cell origin, while a few case studies of T-cell lymphomas of the breast have been reported. The clinical and histologic features of a 74-year-old female diagnosed with T-cell mammary lymphoma are reported, as well as her treatment course and follow-up. A literature review is included. We conclude primary low-grade T cell lymphoma of the breast can be treated with conservative surgery followed by involved field radiation therapy.