Gingival fibromatosis is a rare, benign, slowly-growing fibrous overgrowth of the gingiva, with great genetic and clinical heterogeneity. Gingival fibromatosis/overgrowth can be inherited as an isolated trait (hereditary gingival fibromatosis) and/or as a component of a syndrome, or it can be drug induced. As a clinical manifestation of a syndrome, gingival fibromatosis is usually associated with generalized hypertrichosis, mental retardation, or epilepsy. Gingival fibromatosis and its related syndromes are mainly inherited in an autosomal-dominant manner, but autosomal-recessive inheritance has also been reported. Clinical syndromic presentation includes Zimmermann-Laband syndrome, Ramon syndrome, Rutherford syndrome, Cowden syndrome, Cross syndrome, Göhlich-Ratmann syndrome, Avani syndrome, and I-cell disease. However, a phenotypic overlap has been suggested, as many combinations of their systemic manifestations have been reported. Treatment of choice is usually gingivectomy with gingivoplasty. Before any therapy, clinical practitioners must take into consideration the clinical course of a particular syndrome and every possible functional and esthetic disorder.