Non-alcoholic fatty liver disease (NAFLD) is a common cause of chronic liver disease. Most patients with cryptogenic cirrhosis are considered to have had " burned out NAFLD. " Although the recurrence and progression of NAFLD after liver transplantation (LT) have been shown previously, the incidence of de novo NAFLD after LT has not been extensively reported. In this issue of the American Journal of Gastroenterology , Dumortier et al. report the incidence of de novo post-LT NAFLD. Although most of the risk factors for post-LT NAFLD are similar to those for primary NAFLD, hepatic steatosis in the donor livers and a pre-transplant diagnosis of alcoholic liver disease remain independent risk factors. Although there are some limitations, this study provides the largest cohort of patients for whom post-LT NAFLD is reported. Am J Gastroenterol 2010; 105:621 -623; doi: 10.1038/ajg.2009 Non-alcoholic fatty liver disease (NAFLD) is currently recognized as one of the most common forms of chronic liver disease. Natural history studies have shown that a proportion of patients, especially those with non-alcoholic steatohepatitis (NASH), will develop progressive liver disease, leading to end-stage liver disease and hepatocellular carcinoma ( 1 ). Moreover, recurrence of NAFLD aft er liver transplantation (LT) is common ( 2 ). Th e risk factors for recurrent NAFLD include post-transplant diabetes, obesity, and hypertriglyceridemia ( 1 ). Progression from simple steatosis to NASH and cirrhosis and even allograft failure has been demonstrated ( 1,3 ).De novo NAFLD aft er LT, however, is not as well studied. Its incidence, risk factors, and natural history are not currently well defi ned. In an early report, 25 % of patients with cholestatic liver disease were noted to develop a fatty liver aft er LT. As pretransplant characteristics as well as explants ' histology were not described for this group of patients, it is diffi cult to determine whether this group had concomitant NAFLD at the time of transplantation and thus whether developing a fatty liver aft er transplant simply represented recurrent disease ( 4 ). Poordad et al. ( 5 ) reported four cases of de novo NAFLD that developed early in the post-transplant setting. In another report, NAFLD developed in 40 % of LT recipients aft er a mean follow-up of 44 months ( 6 ). NASH was seen in 13 % . Seo et al. ( 7 ) reported an incidence of 18 % for NAFLD and 9 % for NASH aft er an average follow-up of 28 months. Th ese early reports are, however, limited by small sample sizes and the relative predominance of chronic hepatitis C as an indication for LT, which has been associated with hepatic steatosis, especially HCV genotype 3 infection. Moreover, the liver biopsies in these studies were performed for clinical indications in the majority of cases as opposed to protocol biopsies, a fact that may aff ect the estimation of the incidence of NAFLD in the post-transplant setting.In this issue of the American Journal of Gastroenterology , Dumortier et al. ( 8 ) report their ...