Autogenous bone grafts obtained from the mandibular symphysis or ramus are the primary donor sites for harvesting bone in the oral cavity to correct ridge deficiencies. Although such bone grafts can be successful, several concerns remain, such as donor site morbidity, nerve paresthesia, devitalization of natural teeth, and postoperative complications (eg, swelling, discomfort, and pain). To avoid these concerns and overcome the limited amount of autogenous intraoral bone for grafting, allogeneic block grafts were introduced. The purposes of this paper were to introduce allogeneic block grafts, demonstrate the integration of these allogeneic block grafts into the recipient site by detailed histology, and describe the step-by-step surgical technique of how this graft was used in a patient. A literature search was conducted to identify papers related to allogeneic block grafting, and papers were reviewed and summarized. The advantages and disadvantages of allogeneic block grafting were presented based on the literature and the authors' experience. One patient treated with allogeneic block graft was illustrated. The histologic evidence obtained from this patient indicated good bone remodeling and significant amount of new bone formation. The literature and clinical experience have shown that allogeneic block grafts can be used successfully to augment deficient ridges.