Aims: Massive allografts have been widely employed to replace skeletal defects after bone tumour resection. They have major advantages but the major concern is the long term behaviour of the implant. The aim of the present study was to evaluate the incidence of complications in allograft reconstruction and to describe the new techniques to decrease their rate. Methods: The present series includes 68 patients with 70 massive allografts operated from 1996 to 2002. 35 were males and 35 females with an average age of 31 years (4–79). The massive allograft was used as osteoarticular reconstruction in 28 cases, composite in 28, intercalary in 10, knee arthrodesis reconstruction in 3 and scapular replacement in one case. In 7 cases a vascularized fibula was associated. The femur was involved in 23 cases, the humerus in 16 and the tibia in 17, the pelvis in 7, the radius in 3, the scapula in 2 and patella and a finger in 1 case. Results: Infection rate on 68 cases was 6% (4 cases). All infections healed after surgical revision. Two patients were lost at fu and 10 patients have less than 12 months of fu. The 58 patients left have an average fu of 34 months (12–71). Among these patients 45% had one or more complications treated surgically and 2/3 of the cases healed. Non union rate was 12% and fracture rate 5%. Conclusion: Allograft reconstruction showed a high rate of complications. Almost half of the patients (45%) presented one or more complications which required surgery in 40% of cases. Aggressive antibiotic perioperative regimen and adequate soft tissue coverage of the graft may reduce the risk of infections. Biologic augmentation with vascularized grafts, bone marrow and/or growth factors may reduce non union rate. Cement filling of the graft and composite implant (with prosthesis association) have been introduced in order to decrease the risk of diaphyseal and articular fractures.