Juvenile idiopathic arthritis (JIA) is the most common pediatric rheumatic disease. Children may present to the emergency department during the initial presentation of JIA or due to disease-related complications. Differentiating JIA from emergent causes of joint pain, including severe infections and malignancies, can be challenging. This issue reviews the clinical presentation of JIA, provides guidance for differentiating JIA from conditions with similar presentations, and offers recommendations for management of JIA and JIA-related complications in the emergency department.