The aim of the study is the investigation and comparison the changes in biochemical, histopathological and immunohistochemical pictures in experimentally induced different liver affections including inflammation, fatty change and cirrhosis. Six groups of rats were used; 3 groups experimentally induced hepatic stress by administration of Paracetamol (P) as single dose (1 g /kg b. wt., for 1 day) Fish oil (FO) (35% of total calories) and Thioacetamide (TAA) (200 mg/5 ml saline/Kg. b. wt.,) for 8 weeks and in addition to their controls (3 groups). Serum levels of ALT, AST and total bilirubin were significantly increased in the 3 groups. Furthermore, TAA-treated group showed significant increase in ALP and GGT as well as significant decrease in total proteins and albumin. In addition, there were disturbance in lipid profile and glucose in the three experimental groups. The results of this study demonstrated that P, FO and TAA have hepatotoxic effects, which confirmed by histopathological examinations. Hepatocytes showed hydropic degeneration in diffuse manner Also, Fatty change was observed in diffuse manner all over the hepatocytes in liver of F group. Liver in group T showed distortion of portal areas by fibrous tissue proliferation infiltrated with inflammatory cells.