Drug-induced gingival hyperplasia is a frequent complication of phenytoin anticonvulsant therapy. In severe cases, gingival hyperplasia can cause marked cosmetic deformity, phonatory abnormalities and significant occlusal changes which severely restrict masticatory function. Airway obstruction has not been previously reported with this condition. We describe a unique case of massive phenytoin-induced gingival overgrowth causing glossoptosis and subsequent upper airway obstruction. Possible medical and surgical treatment options, including laser wedge resection of the base of the tongue, are discussed.