Acute limp in a child presents a diagnostic conundrum and can result from a variety of causes. The underlying etiology is often referable to the hip, but the spine, abdomen, pelvis, or knee can be alternatively implicated. An adequate clinical history and satisfactory physical examination are often difficult in younger children. Consequently, there is disproportionate reliance on imaging to arrive at the correct diagnosis. The potential for rapid clinical deterioration and long-term sequelae is a risk with some of the conditions presenting with acute hip (septic hip, osteomyelitis). This review article describes the imaging appearance of common etiologies for acute limp in the ambulatory preschool (1-5 years) and school-age child (5-12 years). The ultimate goal is to familiarize the interpreting radiologist with the imaging appearance of specific clinical entities that lead to acute limp while providing a readily accessible resource on how to image the patient most appropriately and judiciously.