Preoperative evaluation of donors for living-donor liver transplantation aims to select a suitable donor with optimal graft quality and to ensure donor safety. Hepatic steatosis, a common finding in living liver donors, not only influences the outcome of liver transplantation for the recipient but also affects the recovery of the living donor after partial hepatectomy. Histopathologic analysis is the reference standard to detect and quantify fat in the liver, but it is invasive, and results are vulnerable to sampling error. Imaging can be repeated regularly and allows assessment of the entire liver, thus avoiding sampling error. Selection of appropriate imaging methods demands understanding of their advantages and limitations and the suitable clinical setting. This article describes potential clinical applications for liver fat quantification of imaging methods for fat detection and quantification, with an emphasis on the advantages and limitations of ultrasonography, computed tomography, and magnetic resonance imaging for quantifying liver fat.