During the last decade, the role of radiologic modalities in management of patients who have fatty liver disease has expanded. Ultrasonography has been used as a noninvasive alternative to biopsy for monitoring patients who have hepatic steatosis, but MRI is more appealing than ultrasonography to denote minor changes in hepatic fat content. Distinguishing patients who have non-alcoholic steatohepatitis from steatosis alone has become of clinical importance; however, the differences are not apparent with any radiologic modalities. Several modalities have been developed to noninvasively and accurately quantify hepatic fat content and diagnose steatohepatitis. In the future, radiologic modalities might be used to monitor the natural history of the disease or evaluate therapeutic interventions in patients who have non-alcoholic fatty liver disease.