Lesch-Nyhan syndrome is a rare X-linked recessive disorder of purine metabolism, caused by complete absence of the enzyme hypoxanthine-guanine phosphoribosyl transferase. Persons affected with this incurable disease are developmentally and physically delayed, and suffer from self-injurious behavior. The most typical feature results in partial or total destruction of perioral tissues. The purpose of this paper was to discuss a case of Lesch-Nyhan syndrome with self-mutilative behavior and lip injuries, including some suggestions of a preventive approach avoiding the extraction of teeth. A soft mouthguard fabricated to prevent the destruction of perioral soft tissues and combined psychiatric pharmacologic therapy proved to have satisfactory results.