This chapter explores the more common causes of pediatric, nontraumatic musculoskeletal emergencies, thus largely focusing on infectious entities. The spectrum of diseases discussed ranges from mild to severe and includes cellulitis, septic arthritis, osteomyelitis, soft tissue abscess, pyomyositis, and necrotizing fasciitis. As the pediatric population encompasses a large age range from the neonatal period to adolescence, the variability in predisposing factors and clinical presentations among this demographic is highlighted, as well as the differences when compared to the adult population. Imaging, for the majority of the discussed entities, serves as an important tool for guiding diagnosis and management, especially in this young demographic where clinicians often face the unique challenge of the patient’s inability to verbally communicate and/or adequately localize pain. Thus, in addition to elaborating on the details of characteristic imaging appearances of multiple disease processes across different modalities, there is also discussion of when imaging should be considered and how imaging findings can potentially alter patient management.