Lateral pharyngeal diverticulum developes after the herniation of pyriform sinus mucosa and submucosa through the lateral aspect of thyrohyoid membrane between the middle and inferior pharyngeal constrictor muscles or persistent connection of the 3rd branchial anormaly with the pyriform sinus through an internal opening. The most common type of hypopharyngeal diverticula is a Zenker's type which occurs through the weak point between the inferior pharyngeal constrictor and cricopharyngeus, and the lateral pharyngeal type is a very rare variant. The authors experienced a case of lateral pharyngeal diverticum which was treated by surgical excision in a 23-year-old male. The patient was instructed to perform modified Valsalva maneuver under local anesthesia to inflate the sac, and after clamping of its neck, it was removed under general anesthesia without any injury to the superior laryngeal nerve and vessels which were functionally important. It might be a better method in identifying the diverticular sac than endoscopic approach. We report this case with the review of literatures.