Abstract The genealogy of a family with hereditary gingival fibromatosis has been presented. Six marriages between normal and affected persons over four generations resulted in eleven affected children (six girls and five boys) and ten normal children. The defect was transmitted only through an affected parent, the mechanism undoubtedly being a dominant autosomal gene. The clinical and histologic pictures have been illustrated, and the treatment has been described. The literature on hereditary gingival fibromatosis has been briefly reviewed.