The report is devoted to the presentation of aetiological factors causing fatty liver, including alcohol, obesity, diabetes mellitus, hyperlipoproteinaemias and drugs. The author discusses morphological changes typical for the fatty liver such as large or small fatty droplets in hepatocytes and rarely coexisting hepatitis (so-called steatohepatitis). The work presents symptoms, changes in biochemical analyses of serum as well as methods of the liver visualisation used in the diagnostics of fatty liver. The treatment in based on the elimination of aetiological factors and properly balanced diet with support of pharmacotherapy in selected cases

Keywords: Metabolism, Lipids, diabetes mellitus,, Obesity, Alcoholism, Fatty Liver