Nasolabial cyst is a mucus-secreting, nonodontogenic cyst in the nasofacial area. It is usually situated behind the ala nasi, extending backward beneath the nasal floor into the inferior meatus and forward into the labio-gingival sulcus behind the upper lip. Patients with nasolabial cysts generally undergo surgical removal of the cyst via a transoral sublabial approach. This article reports a simple, less invasive surgical procedure for the treatment of nasolabial cysts. A transnasal endoscopic marsupialization method was designed to treat patients with nasolabial cysts. From 1996 through 1998, 16 consecutive patients underwent this new surgical procedure. With patients under local anesthesia, the roof of the cyst, which was firmly attached to the mucous membrane of the anterior nasal floor, was removed transnasally with a sickle knife and scissors. Under the guidance of a nasoendoscope, the opening of the cyst was widened with bite forceps. Meanwhile, the cut edges of the nasal mucosa and the epithelium lining of the cyst were adequately matched. The nose was then loosely packed. All but 1 of the 15 patients were successfully treated with this technique, and the whole surgical procedure was usually completed within 15 to 20 minutes. Postoperative endoscopic and radiological findings revealed that the cyst was replaced by an air-containing sinus with a persistent opening at the anterior or anterolateral nasal floor. There has been no evidence of mucus accumulation in the newly created sinus or recurrence of the cyst during a mean follow-up of 16 months. Transnasal endoscopic marsupialization is a simple and effective surgical procedure for treatment of nasolabial cysts.