Various grafting materials have been used in guided bone regeneration procedures to augment alveolar ridges deficient in horizontal or vertical dimensions or both. Autogenous block grafts from intraoral and extraoral sites have been used for ridge augmentation with encouraging results. However, the risk of vascular and neurologic injury at the donor site as well as postoperative patient morbidity have been reported following these surgical procedures. The use of a cancellous block allograft could be one alternative to avoid potential donor site complications. Five deficient alveolar ridges in three patients were each grafted with a freeze-dried cancellous block allograft and a resorbable barrier membrane. Ridge measurements taken at baseline, graft placement, and a 6-month reentry surgery demonstrated an increase in alveolar ridge width from 2 to 4 mm. These gains in ridge width compare favorably with other guided bone regeneration studies, suggesting that a freeze-dried cancellous block allograft in conjunction with a resorbable membrane may be an acceptable alternative to the autogenous block graft in the treatment of compromised alveolar ridge deficiencies.