This study was designed to prospectively, endoscopically, and histologically determine the prevalence of Barrett's esophagus in patients who had received adjuvant chemotherapy for localized breast carcinoma. Fifteen white women who received cyclophosphamide, methotrexate, and 5-fluorouracil (N = 8) or cyclophosphamide, adriamycin, and 5-fluorouracil (N = 7) chemotherapy underwent esophagogastroduodenoscopy and esophageal biopsy a mean 31.1 months (median, 11 months) after completion of full-course chemotherapy. Twelve of 15 patients had experienced oral ulcerations, diarrhea, or odynophagia during chemotherapy. In no patient was Barrett's esophagus identified endoscopically or histologically. This study fails to demonstrate an increased prevalence of Barrett's esophagus in breast carcinoma patients who had received adjuvant chemotherapy.