Functional and oncologic results of the initial series of children with osteosarcoma treated with rotationplasty at the University of the Philippines - Philippine General Hospital from 2014 to 2015 are reported. Five children (mean 13.2 years) with Enneking IIB osteosarcoma of the lower extremity underwent neoadjuvant chemotherapy, tumor resection with wide margins, and rotationplasty – four Winkelmann Type AI and one Type AII. The four Type-A cases were fixed using an intramedullary nail and the Type A2 case with a plate. Two cases had >90% tumor necrosis. Adjuvant chemotherapy was started 10 to 21 days following surgery. Functional results for the AI rotationplasty showed a good range of motion of the ankle (neo-knee) with preserved muscle strength. The patient with AII rotationplasty had a fair range of motion of the ankle with some muscle weakness. All had radiographic evidence of healing at an average of 12 weeks. The oncologic outcome showed two with local recurrences at five months from surgery; three died of disease at 7, 20, and 38 months; while two are alive without evidence of disease at 72 and 84 months. Three patients were able to fit with a prosthesis with good utility, ambulation status, and satisfaction.