Conclusive evidence of isoniazid (INH)-related hepatotoxicity ranging from asymptomatic elevation of liver enzymes to fulminant hepatic failure resulting in liver transplantation and/or death has been firmly established. Anticipation of the widespread usage of INH in the prevention and treatment of tuberculosis is expected due to the recent increasing incidence of tuberculosis. The aim of this article is to review the current concepts of pathogenesis, histopathology, risk factors and clinical features of INH-related hepatitis, emphasizing the need for vigilance.