Ewing's sarcoma (ES) is a malignant tumor that arises mainly from bone tissue. Primary extraosseous Ewing sarcoma (EES) is a rare form of the Ewing's sarcoma family of tumor, and pelvic localization is even more unusual, considered to be one of the rarest localizations [1]. We present the case of a seven-year-old boy with persistent abdominal pain. Ultrasound (US), contrast-enhanced computed tomography (CECT), and magnetic resonance imaging (MRI) revealed the presence of a large, solid, and heterogeneous mass in the pelvis. The histological and immunohistochemistry were compatible with pelvic EES. Teaching point: Extraosseous Ewing's sarcoma is a rare pediatric tumoral entity that requires clinician and radiological vigilance and detection.