We have studied the protective effect of chitosan on isoniazid- and rifampicin-induced hepatotoxicity with respect to the changes in the levels of diagnostic marker enzymes (in serum), lipid components and lipid peroxidation (in serum and liver). The oral administration of antitubercular drugs caused a significant elevation in the levels of diagnostic marker enzymes and cholesterol, triglycerides, free fatty acids and lipid peroxidation in serum and liver of experimental rats. There was a slight decline in the level of phospholipids in liver tissue also observed. Co-administration of chitosan significantly prevented the antitubercular drugs-induced elevation in the levels of serum diagnostic marker enzymes (alanine amino transferase, aspartate amino transferase, lactate dehydrogenase, acid phosphatase and alkaline phosphatase) in experimental groups of rats. It exerted a significant antilipidemic effect against isoniazid- and rifampicin-induced hepatitis by maintaining the levels cholesterol, triglycerides, free fatty acids and phospholipids in serum and liver at near normalcy. A tendency to prevent the isoniazid- and rifampicin-induced lipid peroxidation was also observed. The results of the present study indicated that the hepatoprotective effect of chitosan might be ascribable to its antilipidemic effect and/or antioxidant property.