Non-alcoholic fatty liver disease (NAFLD) has become the most common liver disease in the paediatric age. The growing prevalence of NAFLD and its advanced phenotype, non-alcoholic steatohepatitis (NASH), in children and adolescents parallels similar trends in obesity and type 2 diabetes mellitus. This trend may have serious long-term implications, including hepatic and extra-hepatic morbidity and mortality, the latter being related mostly due to cardiovascular disease and malignancies. This narrative review, which included 237 articles, summarizes current evidence on paediatric NAFLD, including pathophysiology, risk factors, complications, prevention and treatment (existing and emerging). Early recognition of NAFLD followed by timely and adequate management seems to be important on an individual basis. A global "call to action" regarding paediatric NAFLD seems appropriate to mitigate the burden of this disease.