We report a calcifying odontogenic cyst associated with odontoma (COCaO) and an included permanent canine in the superior maxilla, in a 19 year-old-man. The calcifying odontogenic cyst (COC) was first described as a distinct entity by Gorlin et al in 1962. The lesion is a mixed odontogenic benign tumor, and although most of the cases present cystic characteristics, a few are of the solid type (15%), and its rare malignant transformation is well documented. The COC may occur in association with other odontogenic tumors, the most common is the odontoma, occurring in about 24% of the cases. For this association the term Odontocalcifying odontogenic cyst has been suggested. Radiographically is a well defined mixed lesion and histologically consists of a large cyst. In the central area of the cyst enamel and dentin deposits can be found, irregularly distributed in areas and in other parts it takes on a well defined organoid aspect. A thorough review of literature takes place and the pathogenesis is discussed.