Gingival hyperplasia is characterized by fibrotic gingival overgrowth. The lesion may bury all the crown of the teeth and lead to impairment in masticatory functions and aesthetic disfigurement. This inherited disease is considered rare. We presented two cases of gingival hyperplasia in two siblings: an 11-year-old girl and an 8-year-old boy, whose mother had also suffered from the disease. The two siblings presented with generalized gingival overgrowth involving the maxillary and mandibular arches and covering almost all of the teeth. We performed surgery to reduce the excessive gingivoalveolar tissue and disclosed most of the teeth. The patients showed functional and aesthetic improvement. The last follow-up through a phone call, which was conducted 12 months after the surgery, revealed no recurrent hyperplasia.