An 88-year-old woman was diagnosed with acute cholecystitis and choledocholithiasis on CT. At this point, the gallbladder had become stiff, but the case was not diagnosed as right-sided round ligament. Percutaneous transhepatic gallbladder drainage (PTGBD) was scheduled for choledocholithiasis before cholecystectomy. Exacerbation of inflammatory response and abdominal pain developed the day after PTGBD, with increased peritonitis due to bile leakage noted on contrast-enhanced CT. The round ligament joined the branch of the anterior segment of the portal vein, and the gallbladder was located on the left side of the hepatic ligament. The PTGBD tube punctured the skin, liver, intraperitoneal region and gallbladder, and caused bile leakage. This case shows that there is a possibility of bile leakage due to PTGBD in cases of right-sided round ligament, and therefore, it is particularly important to understand the dissection procedure.