Patients requiring cancellous bone grafting of an extensive deficit or multiple grafting procedures often lack a sufficient quantity of autogenous cancellous donor bone. This study was designed to determine the potential for reharvesting autogenous cancellous bone donor sites in a canine model. Fixed-sized cancellous bone grafts were harvested from the ilium of 12 mature, conditioned dogs. Ilia containing the donor sites were removed from groups of 3 dogs at intervals of 6 weeks, 3 months, 6 months, and 1 year. The donor sites were evaluated by roentgenograms, histology, and histomorphometric analysis and were compared to the opposite, nonoperated ilia, which served as controls. The analysis revealed a gradual replacement of the surgical defect with new cancellous bone by 1 year. Donor site reharvesting is a potential alternative to multiple site grafting or the use of allograft material.