The authors present most common complications after tumor related joint replacement. Twenty-six patients (9 females, 17 males) have been operated on (mean age 22.5 years). In 19 cases osteosarcoma was diagnosed, Ewing sarcoma in 4 and there were 3 cases of chondrosarcoma. Postoperatively, superficial skin necrosis occurred in 4 patients but healed in four weeks, full-thickness skin necrosis in 2 and in 2 cases wound infection resulted in septic loosening of endoprosthesis. The number of infections in our patients was low but caused delay of chemotherapy and need for revision of the infected joint.