A retrospective review was conducted of 49 breast cancer patients who were seen at the Massachusetts General Hospital from 1962 to 1978 and who developed biliary tract metastases. Although these findings were incidental at autopsy in 21 patients, clinical evidence of extra-hepatic biliary involvement developed in 28. This was documented radiographically, surgically, and/or confirmed at autopsy. Although most patients had previous or concurrent nonbiliary tract metastases, in 6 patients the initial site of failure was in the extra-hepatic biliary system. Analysis of the 28 patients in the clinical group revealed that initial management with radiation therapy alone produced a response in 3 of 6 patients. However, when radiation was coupled with bypass surgery and/or adjuvant chemotherapy, a response occurred in 3 of 3; the total radiation therapy response rate was 6/9. Chemotherapy given either alone or in combination with surgery produced a response in only one of 7 patients. All 4 irradiated patients who were treated with a time-dose-fractionation (TDF) > 40 had a complete response compared to a complete response in only 2 of 8 with a TDF ≤ 40. The median survival of the irradiated group was 6 months compared to 3.3 months in the treated-unirradiated patients and 0.7 months in the untreated patients. The onset of jaundice in a breast cancer patient does not necessarily indicate progressive hepatic involvement. Patients with extrahepatic metastatic obstruction are being recognized increasingly and should be treated vigorously, especially since such patients with no liver parenchymal involvement have a greater survival (median 6 months) than those with liver involvement (median 1.8 months).