Liver masses in children with underlying systemic disease or a predisposing syndrome can be benign or malignant, ranging from focal fat to hepatocellular carcinoma (HCC). Knowledge of the underlying condition, the pathophysiologic effect on the liver, and the development of liver disease and specific liver lesions allows radiologists to guide imaging with regard to modality and frequency and give recommendations for biopsy when appropriate. In some predisposition disorders, such as Beckwith Wiedemann spectrum, familial adenomatous polyposis syndrome, and tuberous sclerosis complex, established guidelines for imaging screening exist. In many of the syndromes discussed, masses may occur outside of the liver and the liver may not be the primary focus of screening. For other entities, no consensus recommendations exist. Screening recommendations may be based on the risk of development of chronic liver disease. Once cirrhosis occurs, the risk of developing HCC is elevated. The authors summarize the spectrum of liver lesions that may be encountered in children with predisposing syndromes and systemic diseases, the imaging appearance of the lesions with various modalities, and screening guidelines where published. ©RSNA, 2024 See the invited commentary by Rutten and Chavan in this issue.