Five children with pelvic Ewing's sarcoma whose age was 6-10 years underwent reconstruction after resection of the tumor. One child with a tumor of the ilium underwent an iliosacral arthrodesis with allograft. Three patients underwent a hip transposition after the resection of the ilium and the upper part of the acetabulum. One patient underwent no skeletal reconstruction after the resection of the acetabulum and the ilium. Two children are alive 96 and 60 months after surgery; however, two died 12 and 21 months after surgery of metastasis, and one is alive with metastasis 15 months after surgery. Functional evaluation was possible in four patients: one is excellent, and three are fair. After resection of the ilium, including the upper part of the acetabulum, a hip transposition can be selected. If all the acetabulum is resected, it will be optimal not to do a bony reconstruction.