Twelve patients with discharge of clear colorless fluid during percutaneous transhepatic gallbladder drainage (PTGBD) were encountered during a period of 4.5 years. On the average, the fluid appeared on the 12th day after PTGBD and continued to flow until the completion of observation. The volume was usually less than 60ml per day. It flowed in an alternating pattern with normal yellow color bile each day. The fluid was observed in patients in whom satisfactory patency of the biliary system was confirmed by cholangiography and/or cholangio-fiberscopy. Biochemical examinations of the fluid revealed lower biliary lipids but a similar electrolyte composition compared to bile of normal color. It was alkaline. These observations indicate that the clear colorless fluid is different from what is known as “white bile”, which is produced when there is an obstruction of the biliary tree. The fluid may be secreted from the gallbladder epithelium or the bile duct epithelium. The significance was not clarified in this study. Further investigation is necessary to elucidate the clinical implications of the clear and colorless fluid secretion.