We evaluated the 2- to 7-year results of a rotating-hinge knee replacement after excision of malignant tumors of the knee joint. There were 25 distal femoral and 7 proximal tibial replacements. The 5-year prosthetic survival for distal femoral replacements was 88%, compared with 58% for proximal tibial replacements. Seven patients underwent prosthetic exchange: 1 for aseptic loosening, 2 for wound slough and perioperative infection, and 4 for articulating component failure. One patient underwent above-knee amputation owing to skin necrosis. The median functional scores at the latest follow-up were 27 by the International Society of Limb Salvage evaluation system and 80 by the Hospital for Special Surgery Knee Score system. This implant is a promising choice for joint reconstruction after excision of tumors at the knee joint.