Aim:The aim of this article is to present a case of a phenobarbital-induced gingival hyperplasia (GH), discuss possible etiological mechanisms of drug-induced GH, and to present a concise review of the literature.Background: GH is a well-known complication associated with anticonvulsant phenytoin, antihypertensive calcium channel blockers, and immunosuppressant cyclosporine therapy. Sodium valproate and primidone has very rarely been found to cause GH. Report: An extremely rare case of phenobarbital-induced GH in a 28-year-old male patient who had received this drug for three years is presented. The histological examination of the lesion revealed a hyperplastic epithelium, epithelial acanthosis, and elongated rete ridges as well as obviously enhanced dense collagenous fibers and proliferation of fibroblasts. Summary:Phenobarbital-induced GH is a rare clinical entity which necessitates meticulous evaluation. However, it seems to show a benign behavior with reference to recurrence after surgical excision. Citation: LafziA, Farahani RMZ, Shoja MAM. Phenobarbital-induced Gingival Hyperplasia. J Contemp Dent Pract 2007 September; (8)6:050-056. Abstract © Seer Publishing