Background: Crowding is one of the most popular stressors in experimental medicine since it could be regulated easily. Social isolation and lack of social support have deleterious effects on health. These are regarded as one of the most relevant causes of human diseases. Objective: Evaluation of the possible effects of either crowding and loneliness on liver functions in adult male albino rats. Material and methods: Fifty four adult local strain male albino rats were chosen as a model for the present work. They were divided into equal three groups;control group, crowded group and reduced space group. Animal behavior was observed, and blood samples were obtained for determination of blood glucose level, total cholesterol, triglycerides, low density lipoprotein (LDL), high density lipoprotein (HDL), alanine aminotransferase (ALT), aspartate aminotransferase (AST), total serum protein, serum albumin and globulin. Liver samples were obtained for histopathological study. Results: Crowding or loneliness led to different homeostatic changes including disturbed liver functions, glucose metabolism, lipid profile and altered behavior in addition to marked cellular changes on histopathological examination.  Conclusion: Housing conditions affected behavioral and biological responses of animalsand could be considered risk factors for certain diseases as diabetes mellitus, dyslipidemia and liver injury. Further studies are required to demonstrate how chronic stress can exert a facilitative effect on inflammatory response and even increases the risk of developing pathological effects.