Nonalcoholic fatty liver disease (NAFLD) is a global health dilemma. The gold standard for diagnosis is liver biopsy. Ballooned hepatocytes (BH) are histologic manifestations of hepatocellular injury and are characteristic features of steatohepatitis (SH), the more severe and potentially more progressive form of NAFLD. Definitive histologic identification of BH on routine stains, however, can be difficult. Immunohistochemical (IHC) staining for loss of the normal hepatocytic keratin 8/18 (K8/18) can serve as an objective marker of BH. We sought to explore the utility of a K8/18 plus ubiquitin (Ub) double IHC stain for the histologic evaluation of adult NAFLD.