Transjugular liver biopsy is widely used in adult patients with liver disease when transthoracic needle liver biopsy is contraindicated by severe coagulopathy or ascites. It has not been used extensively in children. We report our experience with 30 consecutive transjugular liver biopsy procedures performed in 27 young patients at the Hospital for Sick Children in Toronto. Patient weights ranged from 14 to 91 kg (median = 42 kg); most patients had not yet attained adult size. A 9F catheter was used except in very small children, for whom we developed a 7F biopsy needle catheter. Most procedures were done with patients under general anesthesia. Specimens were obtained in all patients, and the procedure was tolerated well. A major complication occurred only once: perforation of the inferior vena cava, which was later repaired at liver transplantation. Minor complications included subcapsular extravasation of contrast agent in five patients and a small intrahepatic hematoma in one. Results of transjugular liver biopsy changed the diagnosis in 30% of patients and added valuable information about the disease process in most patients. Transjugular liver biopsy was an important component of emergency assessment for liver transplantation. Our results indicate that transjugular liver biopsy can be performed safely in children with liver disease if a skilled interventional radiologist and a well-equipped angiography suite are available. Histological studies in these patients enhance our understanding of the natural history of pediatric liver diseases. (HEPATOLOGY 1992;15:1036–1042).