Obesity has various effects on hepatic function. There is little information available for effects of exercise on biochemical and histopathological changes in the liver of obese rats. In addition the prevalence of cigarette smoking (CS) is increased among obese subjects, who are susceptible to develop fatty liver disease (FLD). The objective of this study was to assess the effects of exercise and passive smoking on body mass index, serum lipid profile, blood glucose, aspartate aminotransferase (AST), alanine aminotransferase (ALT), albumin level and liver histology in rats fed high-sucrose diet. The rats included in this study were classified into 5 main groups; groupI: control group, group II:high Sucrose untrained group not exposed to passive smoking ,groupIII: high Sucrose trained group, group IV: high Sucrose group exposed to passive smoking, groupV: high Sucrose trained group and exposed to passive smoking. From this study we can conclude that, obesity that induced by high sucrose diet caused significant increase in body mass index, serum triglycerides, total cholesterol ,LDL.C, blood glucose, aspartate aminotransferase (AST) and alanine aminotransferase (ALT)as well as significant decrease in albumin and serum HDL.C with significant changes in liver histology. All these effects were counteracted by exercise and were ameliorated by smoking. preventing and treating obesity will be a key measure in preventing and controlling this epidemic of fatty liver disease.