The odontogenic keratocyst (OKC) is a developmental odontogenic cyst accounting for approximately 3%-17% of cysts of the jaws. This is an uncommon lesion both clinically and pathologically because of the unusual growth pattern and high tendency for recurrence. The recommended surgical management of the lesion varies from marsupialisation to en bloc resection. In the treatment of a large mandibular OKC, enucleation and immediate bone grafting maintains mandibular integrity, reduces the risk of pathological fracture permits restoration of function with implant-supported prostheses. We recommend the following protocol in the management of large mandibular OKC: 1. Biopsy of the lesion. 2. CT scans in axial and coronal planes. 3. Enucleation of the cyst and removal of the associated teeth. 4. The excision of the overlying mucosa. 5. Immediate mandibular reconstruction with a corticocancellous iliac crest bone graft. 6. Placement of endosseous implants four months following bone grafting. 7. Reconstruction of the dentition six months following implant placement.