The nasolabial cyst is an uncommon midfacial cyst. Twenty-six patients with nasolabial cysts were treated at the New York Eye and Ear Infirmary from 1969 to 1986. Most of these lesions manifested facial deformity, unilateral nasal obstruction, and pain when infected. The nasolabial cyst is often unrecognized or confused with other intranasal masses, or fissural and odontogenic cysts. Infection of these lesions--which occurred in 50% of the patients--may mimic facial cellulitis, periodontal abscess, acute maxillary sinusitis, or nasal furuncles. This cyst is considered to be a hamartoma because of its developmental origin from entrapped epithelium in an embryonic fusion plane. Simple aspiration invariably leads to recurrence, and complete surgical excision is the accepted treatment. The nasolabial cyst should be considered in the differential diagnosis of intranasal masses, midface infections, and swelling in the nasolabial area.