Primary breast lymphoma is a rare disease. It represents only 0.12% to 0.30% of all female breast malignancies. Few cases were sporadically reported. Due to the paucity of patient data, there is no standard treatment protocol for primary breast lymphoma. We reported two cases of primary breast lymphoma treated with chemotherapy followed by radiotherapy. Tumor regression with no residual disease was achieved after treatments. No relapse was developed in the follow-up period. We also reviewed the literatures on primary breast lymphoma to evaluate treatment outcome and prognosis.