Bile leak remains a serious complication after hepatectomy. The conventional leak test by intrabiliary injection of normal saline solution is not sensitive. The authors present a new bile leak test using indocyanine green (ICG) fluorescence. After hepatic transection, ICG solution (.05 mg/mL) was intrabiliarily injected through a transcystic tube under distal common bile duct clamping, and fluorescent images were visualized using an infrared camera system. The ICG leak test was performed in 27 patients undergoing hepatectomy without biliary reconstruction. Bile leaks were intraoperatively found in 8 patients and fixed, resulting in no postoperative leaks. There was no adverse reaction to ICG. In contrast, postoperative bile leaks occurred in 2 of 32 patients who received the conventional leak test with normal saline solution between April 2007 and March 2008. The new bile leak test by ICG fluorography is useful to prevent postoperative bile leak.