Non-alcoholic fatty liver disease (NAFLD) is characterized by liver fat accumulation and non-alcoholic steatohepatitis (NASH) with inflammation and fibrosis, which may lead to cirrhosis also in childhood. NAFLD/NASH in children are related to obesity and the metabolic syndrome, and incidence and prevalence are expected to increase. Children having liver steatosis and elevated liver enzymes are most often asymptomatic, and a liver biopsy is necessary for correct diagnosis and staging. The treatment should focus on lifestyle changes, as pharmacological therapy needs further evaluation.