To obtain a histopathologic diagnosis at the site of a biliary obstruction, we recently have performed 24 cases of biliary biopsy using gastrofiberscopic biopsy forceps (Olympus, Tokyo, Japan) via transhepatic tracts provided in the course of the procedure of percutaneous biliary drainage. Histopathologic diagnosis was successfully made at the first attempt of biopsy procedure but a second trial was made a week later in 6 cases who were negative for malignant cells on the first attempt. The histological results from the biopsy specimens were 18 adenocarcinomas, 5 chronic inflammations and one normal epithelium. Of 6 cases who were negative for malignant cells on forceps biopsy specimen, three cases were confirmed as adenocarcinoma of the ampulla of Vater, adenocarcinoma of the pancreas and chronic pancreatitis by surgical biopsy. The latter was a true negative result, which was diagnosed as chronic inflammation on forceps biopsy and verified as chronic pancreatitis by surgery. The remaining two cases were diagnosed as malignant obstructive jaundice by clinical and radiological follow-up findings. Major complications (bile peritonitis, bleeding, and hemopneumothorax) occurred in 3 patients, which mainly arose in the earlier period of study. This procedure can be performed at the same time as percutaneous transhepatic biliary drainage with low morbidity or mortality, and although the potential for perforation of bile ducts and injury to adjacent blood vessels is considered it is a useful addition to existing biopsy techniques for yielding material sufficient for histologic analysis.