Due to the current obesity epidemic, non-alcoholic fatty liver disease (NAFLD) is prevalent in a significant portion of the United States patient population. It is being increasingly recognized that NAFLD affects both adults and children and can progress to end stage liver disease with resultant cirrhosis, portal hypertension, and hepatocellular carcinoma. In addition, several extrahepatic conditions may be linked to NAFLD including cardiovascular disease, insulin requiring and type 2 diabetes mellitus, obstructive sleep apnea, colonic adenomas, hyperuricemia, vitamin D deficiency, hyperferritinemia, pancreatic steatosis, hypothyroidism, and polycystic ovarian syndrome. Therapies for NAFLD are evolving rapidly. This issue will analyze patient demographics, risk factors, pathophysiology, patient presentation, and treatments for NAFLD.