Biliary obstruction secondary to colorectal cancer liver metastases is associated with a poor prognosis especially when chemotherapy cannot be re-started. The aim of this study was to determine the survival after biliary drainage and the associated prognostic factors. METHODS: Patients from two French centers were included retrospectively after first biliary endoscopic retrograde cholangiopancreatography or percutaneous transhepatic cholangiography drainage for biliary obstruction secondary to liver metastases of colorectal cancer, occurring during chemotherapy. RESULTS: The final analysis included 69 patients. Overall median survival was 115 days. In univariate analysis, a previous liver surgery, technical and functional success of drainage and restarted chemotherapy were significantly associated with an improved survival. Chemotherapy was restarted after a median of 27 days. When drainage was efficient, survival improved from 33 to 262days (p<0.001). In multivariate analysis, significant protective factors for survival included previous a hepatectomy (HR 0.41) and functional success of the drainage (HR 0.29). Predictive factors for death included increased lines of chemotherapy (HR 1.68) and fever before drainage (HR 2.97). CONCLUSIONS: This is the first study concerning the benefits of biliary drainage for malignant biliary obstruction during the course of chemotherapy for colorectal cancer. A successful biliary drainage leads to improved survival and allows achievement of chemotherapy for 70% of patients.