Hereditary gingival fibromatosis is characterized by a slow, progressive increase in the gingival tissue that develops as either an isolated disorder or as part of the clinical characteristics of diverse syndromes. The present case report describes a Brazilian family with individuals from three generations affected. The proposed treatment was maxillary and mandibular gingivectomy with 12 months of monitoring. Keywords: collagen disorder, gingival enlargement, hereditary gingival fibromatosis