Objective To investigate PTCH gene mutations in odontogenic keratocysts(OKC). Methods PCR- SSCP and DNA sequencing were used to analyze the PTCH gene mutations in 12 OKCs, including 10 sporadic and 2 nevoid basal cell carcinoma syndrome(NBCCS) associated OKC. Results Four mutations were identified in 4 cysts,among which two germline mutaions were associated with NBCCS and 2 somatic mutations were in 2 unrelated sporadic cases. In addition, eight previously reported polymorphisms in the PTCH gene were also found in 10 cases. Conclusion The present study indicated that both sporadic and NBCCS-related OKCs could carry PTCH gene mutation. Thus, mutational inactivation of PTCH gene may play a significant role in the pathogenesis of OKC.