A study was undertaken to evaluate the long term results of root resections. Records of 100 patients who had undergone root resections 10 years prior to the study were reviewed. Although the immediate postoperative results were gratifying, they were not always lasting. Eighty-four per cent of the failures occurred after 5 years. Most failures were in the mandibular arch and derived from reasons other than inflammatory periodontal disease. Suggestions are made as to how to improve the prognosis of resected teeth.