Liver tumors in the pediatric age group exhibit a range of cellular differentiation: hepatoblastomas typically show relatively undifferentiated neoplastic hepatocytes, hepatocellular neoplasms (not otherwise specified) present with moderately differentiated cells, and hepatocellular carcinomas display more mature-appearing hepatocytes. As histogenesis is a continuous process, there is considerable morphological overlap between these entities. Hepatoblastomas, the most common primary malignant liver tumor in children, exhibit various morphologic patterns, including epithelial components with varying degrees of differentiation and variable mesenchymal elements. The overlaps between different tumor types and the intralesional variations within a single disease can present diagnostic challenges. This chapter discusses the detailed morphologic features of liver tumors predominantly seen in children, including hepatoblastoma, mesenchymal hamartoma, embryonal sarcoma, and infantile and congenital hemangiomas, in the context of clinical presentation and laboratory findings. It also reviews current molecular advances that aid in diagnosis. Certain liver tumors, such as calcifying nested stromal-epithelial tumors, hepatocellular adenomas, hepatocellular carcinomas, hemangioendotheliomas, and angiosarcomas, occur in both children and adults, and are diagnosed using identical histologic criteria regardless of the patient’s age. We explore the differences between hepatocellular carcinoma in children and adults and highlight the key features of calcifying nested stromal-epithelial tumors.