This chapter primarily explores the classification of liver trauma, which serves as a crucial basis for assessing the condition, determining suitable therapeutic strategies, and forecasting prognosis. Two widely adopted classification systems are the American Association for the Surgery of Trauma (AAST) liver injury classification and the World Society of Emergency Surgery (WSES) classification system for liver trauma. The AAST classification system categorizes liver injuries into Grades I–VI, with updated editions in 1994 and 2018 offering detailed descriptions of the extent of damage, particularly emphasizing the definition of vascular injury. Conversely, the WSES classification system emphasizes the physiological implications of liver trauma, classifying it as mild, moderate, or severe, while also considering the patient’s overall physical condition and any associated complications to aid in the management of liver trauma. Both classification systems, as integral tools in the medical arsenal, harbor unique importance and are tailor-made for specific clinical contexts, where they showcase their distinct applicability and relevance.