Alopecia neoplastica is defined as hair loss secondary to a visceral malignancy that has metastasized to the scalp. We describe a woman with adenocarcinoma of the breast who developed alopecia neoplastica while receiving antineoplastic therapy. Alopecia neoplastica has been observed in 25 women. Breast cancer was the primary malignancy in 84% of patients with alopecia neoplastica. Other primary tumors whose metastases presented as neoplasm-related hair loss each occurred in one individual with gastric carcinoma, colon carcinoma, cervical carcinoma, and trophoblastic tumor.