['To evaluate the downstaging efficacy of yttrium-90 radioembolization (Ytt-90)-associated with chemotherapy and the results of surgery for initially unresectable huge intrahepatic cholangiocarcinoma (ICC).', 'Between January 2008 and October 2013, unresectable ICC were treated with chemotherapy and Ytt-90. Patients with unique tumors localized to noncirrhotic livers and without extrahepatic metastasis were considered to be potentially resectable and were evaluated every 2 months for possible secondary resection.', 'Forty-five patients were treated for unresectable ICCs; ten had potentially resectable tumors, and eight underwent surgery. Initial unresectability was due to the involvement of the hepatic veins or portal vein of the future liver remnant in seven and one cases, respectively. Preoperative treatment induced significant decreases in tumor volume (295 vs. 168 ml, p = 0.02) and allowed for R0 resection in all cases. Three patients (37.5 %) had Clavien-Dindo grade three or higher complications, including two postoperative deaths. The median follow-ups were 15.6 [range 4-40.7] months after medical treatment initiation and 7.2 [0.13-36.4] months after surgery. At the end of the study period, five patients were still alive, with one patient still alive 40 months after medical treatment initiation (36.4 months after surgery); two patients experienced recurrences.'] Is intra-arterial yttrium-90 radioembolization combined with systemic chemotherapy a promising method for downstaging unresectable huge intrahepatic cholangiocarcinoma to surgical treatment?