This document provides guidance on evaluating and treating a child presenting with vomiting. It begins with definitions of related terms like nausea, retching, and regurgitation. It then reviews the major neurophysiological pathways that can induce vomiting. Etiologies are discussed including central, infectious, metabolic, and peripheral causes. An approach is outlined involving obtaining a thorough history and physical exam to determine potential causes and guide testing. Common etiologies are reviewed for different age groups. Complications, treatment principles targeting the underlying cause, and sick day management for diabetes are also summarized.