Rhabdomyosarcoma is the most common tumor of the biliary tract in children. Although some features at preoperative radiographic studies (ultrasound, CT, MRI) may be suggestive of BT-RMS, until few years ago the final diagnosis was obtained by either operative or transcutaneous biopsy, thus exposing to a risk of regional dissemination. More recent and still anecdotal, is the histological diagnosis on tissue obtained by transluminal biopsy either during transhepatic cholangiography or endoscopic retrograde cholangio-pancreatography (ERCP), the latter having the major advantage of a much lower risk of loco-regional dissemination. We present two cases of BT-RMS that were histologically diagnosed by intracholedocal biopsy performed during ERCP, after being suspected at conventional imaging.