We reviewed the results of 104 intercalary allograft procedures that had been performed, between April 1974 and August 1992, in 100 patients, usually after resection of a segment of bone because of an osseous neoplasm. The median duration of follow-up was 5.6 years. Retention of the graft and return to essentially normal function were the measures of success and, on that basis, eighty-seven (84 per cent) of the 104 reconstructions were successful. Of the fifteen limbs in which the reconstruction failed, four were salvaged with insertion of a second allograft and three, with use of some other technique. Of the 104 allograft procedures, eight (including two in patients who had a recurrent tumor) were followed by an amputation; thus, the ultimate rate of salvage was 92 per cent for the entire series. Thirty-one grafts failed to unite at one junction with the host or both, within one year after the operation, and this necessitated eighty-one additional operative procedures to achieve a good result. Life-table regression analysis showed that age, gender, anatomical site, and length of the graft were not associated with significant differences in the over-all outcome. Infection (p = 0.0001); fracture (p = 0.002); stage of the lesion (p = 0.007); and use of adjuvant chemotherapy or radiation, or both (p = 0.008), all had an adverse effect on the survival of the allograft. Despite the relatively high rate of non-union that necessitated additional operations, these data indicate that transplantation of allografts for the treatment of intercalary defects has a high rate of success and usually results in a functional limb.