Gingival Fibromatosis is characterised by a large increase in the gingival dimension which extends above the dental crowns, covering them partially or completely. The causes of the disease may have a genetic origin, in which case gingival hyperplasia may occur in isolation or be part of a syndrome, or acquired origin, which comes from specific drugs administered systemically. A form of gingival fibromatosis of idiopathic origin has been described. The therapy involves mainly the surgical removal of the hyperplastic gingival tissue, although in these cases recurrences are frequent.A 9 years old male patient came to observation at the Clinic of Pediatric Dentistry of the Tor Vergata Polyclinic of Rome. After Primary Gingival Fibromatosis was diagnosed, the therapeutic choice was to wait and postpone gingivectomy at the end of the development phase.