A case of bilateral breast cancer associated with von Rechlinghausen's disease is reported. [First cancer: left breast cancer] A 47-year-old woman was admitted to the hospital because of a left breast tumor with a gradual grouth for two years. The left breast tumor was measured 7.0cm in diameter and multiple neurofibromas and cafe'au lait spots were scattered on the entire skin surface. Modified radical mastectomy was performed under the diagnosis of breast cancer. Histologically, the tumor was papillotubular carcinoma without metastasis to the axillary lymph node. [Second cancer: right breast cancer] A right breast tumor 2.5cm in diameter was detected 3 years after the resection of the left breast cancer. Modified radical mastectomy was performed under the diagnosis of breast cancer. Histologically, the tumor was papillotubular carcinoma with intra-ductal component, and no metastasis to the axillary lymph node. was revealed. Clinically and histologically, metachronous bilatelal breast cancer was diagnosed.