The purpose of this study was to report clinical characteristics, surgical results, and new PTCH1 gene mutations in nevoid basal cell carcinoma syndrome (NBCCS). Five patients were referred to the Department of Oral and Maxillofacial Surgery from local dental clinics between 2006 and 2016 to treat multiple keratocystic odontogenic tumors (KOTs). The cystic lesions were enucleated and peripheral ostectomy was performed to obtain safety margin. Recurrence and/or de novo development of KOT were assessed. Gene analysis using peripheral blood was performed in all patients to identify the mutation of PTCH1 gene. Three patients showed familial history of first-degree relatives. Of the major criteria, all patients presented KOT but only 1 patient had basal cell carcinoma. Of the minor criteria, 4 of the 5 patients presented macrocephaly and hypertelorism. During follow-up periods, all patients showed recurrence and/or de novo development of KOT in the jaw bone. Mutation analysis of PTCH1 gene showed 3 frameshifts (c.817_818ins(T), c.1226_1227ins(A), and c.2748del(C)), 1 splicing (c.1504-2A>T), and 1 missense (c.385T>C) mutation. Mutations were found in exon 1, 6, 9, 17, and intron 10. Regular follow-up is necessary because recurrence rate of KOT was very high. To help early diagnosis, it is essential to routinely perform genetic testing to detect PTCH1 gene mutations among patients with NBCCS.