BACKGROUND AND PURPOSE The odontogenic keratocyst (OKC) is an unusual cyst with a high recurrence rate. The most common site for OKCs is by far the mandible. The best treatment of OKC remains controversial. Recurrence rates ranging anywhere from less than 10% to more than 60% have been reported. The aim of our study was to evaluate marsupialization as a treatment option for OKC. METHODS We managed 13 patients (8 male, 5 female) between the ages of 16 and 31 years (mean, 22.4 y) with biopsy-proven OKC. Radiographically, the patients' cyst sizes were between 25 and 90 mm. Treatment consisted of marsupialization. We followed up with patients for a total duration of at least 60 months, and posttreatment visits were carried out at 6-month intervals. RESULTS We documented cured or reduced cyst size with radiography. The odontogenic keratocyst resolved completely in 10 patients, and the cyst walls shrank in 3 patients. The latter patients required a second operation to remove the associated impacted teeth. A histologic evaluation of 3 lesions showed metaplasia. Any case of recurring cysts was not seen during the entire follow-up period. CONCLUSIONS Marsupialization is an effective and conservative treatment option for OKC. Nevertheless, future studies should conduct even longer follow-up periods to evaluate any recurrence of lesions.