Ameloblastoma, the most common odontogenic tumor in sub-Saharan Africa, has initial clinical features of painless, slow growth that sometimes results in giant sized, neglected, or gigantic lesions, often called giant ameloblastoma. The definition of giant ameloblastoma is controversial, their full characteristics, especially tumor growth rate, are yet to be fully elucidated, but their large sizes make management quite challenging. This case report presents giant mandibular ameloblastoma that developed over 10 years in a 30-year-old male. The lesion extended from one ramus to the other, measuring 48 cm × 38 cm × 17 cm. The treatment was segmental resection of the lesion after preoperative tracheostomy. Reconstruction was by retaining jaw form using the titanium reconstruction plate due to inability to perform free-bone grafts in this environment. There is need for universal health insurance in Nigeria to improve financial access to health-care services. Improved technical skill of surgeons and other clinical staff will also assist to optimize the treatment outcomes for patients with giant-sized lesions.