Acute liver failure (ALF) is a clinical syndrome associated with significant morbidity and mortality with a highly unpredictable outcome. We retrospectively analyzed 71 ALF patients (53 males; mean age = 27.5 ± 15.6 years) that underwent transjugular liver biopsy (TJLB) at our institution. The aims of this study are (i) to report our experience with TJLB in these patients, and (ii) to examine the role of liver histology in predicting their outcome. We also compared the histopathological findings between TJLB and explanted liver specimens in 31 patients who underwent liver transplantation (LT). Biopsy specimens were satisfactory for histopathological analyses in 69 (97.1%) patients, confirmed the clinical diagnosis in 56 (81.2%) patients, and altered the diagnosis in 13 (18.8%) patients. Minor complications were encountered in four (5.6%) patients. Percentage of hepatocyte necrosis was the only histological parameter that has significant discriminatory prognostic value, with no survivors having >75% necrosis without LT. In conclusions, TJLB is a safe technique for obtaining liver tissue in both adult and pediatric patients with ALF. Histological characteristics, mainly etiological diagnosis and degree of hepatocyte necrosis may assist in clinical decision-making for need of LT in these patients.