The incidence of non-alcoholic steatohepatitis, a disorder linked to visceral adiposity, insulin resistance, dyslipidemia, and type 2 diabetes mellitus, is increasing with the rise in the prevalence of the metabolic syndrome. This review focuses on animal models of steatohepatitis currently used to study (1) the mechanisms regulating hepatic lipid, glucose, and cholesterol homeostasis and (2) inflammatory recruitment and fibrogenesis in the steatotic liver. The ultimate aim of this research is to gain insights into the role of hepatic lipid, inflammation, and fibrosis in human non-alcoholic fatty liver disease.