Large osseous defects secondary to resection of the mandibular segment may lead to significant facial deformity, functional disabilities, and associated psychologic problems. The therapeutic approach is more complicated in pediatric patients because it must not interfere with normal craniofacial growth process. Here, we present a clinical report to emphasize the application of extraoral short implants with magnetic abutments used for mandible of a growing patient reconstructed with free iliac flap after resection of Ewing sarcoma. A 5-year-old boy, complaining of an ulcerated mass of the anterior mandibular area and floor of the mouth, was referred to our clinic. Incisional biopsy from the lesion confirmed the diagnosis of Ewing sarcoma. After resection, free iliac osteocutaneous flap, with a 6.5 x 4.0-cm skin paddle and based on the deep circumflex iliac vessels, was used to reconstruct the mandibular integrity and to cover the floor of the mouth simultaneously. Nine months after the operation, the patient was referred for oral rehabilitation. Prosthodontic plan included the placement of 5 extraoral implants with magnetic abutment and fabrication of an implant-retained overdenture. Magnetic abutment was preferred not to interfere with the expected craniofacial growth. During a follow-up period, radiographic images showed no pathologic signs with consideration of overall bone loss and recurrence of the tumor; 12 months after the initiation of prosthetic loading, no peri-implant bone loss was observed. In conclusion, this reported case would be an example for the management of challenging pediatric mandibular tumor cases in terms of resection, reconstruction and dental rehabilitation.