Drug-induced gingival enlargement has been reported in patients treated with various types of anticonvulsant drugs, and is generally associated with the presence of plaque, gingival inflammation, and a genetic predisposition. Effective treatment includes daily oral hygiene and periodic professional prophylaxis. However, in some patients, surgical removal of the gingival tissue overgrowth becomes necessary. The patient in this case report was mentally impaired and had severe drug-induced gingival enlargement. This report describes the initial protocol, the gingivectomy, and a 2-year follow-up. A diode laser was used as an effective and safe method to remove the patient's overgrown gingival tissue.