Since 1975, nine patients who had adamantinoma of the tibia were treated by the orthopaedic oncology service of the Massachusetts General Hospital and the Children's Hospital, Boston, Massachusetts. All patients were followed for two years or more or until a relapse occurred (mean length of follow-up, 5.3 years). Five of the patients were female and four were male; their ages ranged from fourteen to fifty-six years (mean, 19.1 years). The treatment consisted of staging, wide surgical resection of the tumor, and insertion of a segment of intercalary bone allograft (eight patients) or an osteoarticular segment (one patient). All grafts were fixed with compression plates and screws. All but two of the allografts had united at both the proximal and the distal host-donor junction site by twelve months. None of the patients had a local recurrence but pulmonary metastases developed in one. Four of the patients had complications that affected the final result. The functional results were excellent in five patients, good in one, fair in one, and a failure in two. Seven of the nine patients were asymptomatic and fully functional at the time of writing; only one needed a brace to walk. On the basis of this experience we recommend wide resection and implantation of an intercalary allograft in the treatment of adamantinoma of the tibia.