A retrospective study was performed between 1980 and 1995 on 38 recipients of proximal tibial allografts after wide resection of benign and malignant tumors. Twenty-one (55%) patients experienced one or more complications. Of the 26 patients who received chemotherapy, 15 (58%) experienced one or more complications, whereas of the 12 patients who did not receive chemotherapy, six (50%) experienced one or more complications. In the chemotherapy group, there were 12 (46%) fractures, four (15%) infections, three (12%) nonunions, and four (15%) instabilities. In the nonchemotherapy group there were three (25%) infections, two (17%) fractures, one (8%) instability, and one (8%) nonunion. These complications were managed adequately with multiple subsequent surgical procedures. Three patients underwent amputations for deep wound infections. Twelve (32%) patients underwent removal of the allograft, and the limb was salvaged by reallografting or by total knee arthroplasty. The results of both groups were 66% (25 of 38 patients) satisfactory (good or excellent). The chemotherapy group had a significantly higher incidence of fractures. All other complication rates and functional outcomes were not significantly different between these groups.