The calcifying odontogenic cyst is a rare lesion that exhibits features of both a cyst and a solid neoplasm. It was first described as a separate entity in 1962 by Gorlin and his colleagues. In 1971, the World Health Organization defined the calcifying odontogenic cyst as "a non-neoplastic cystic lesion in which the epithelial lining shows a well-defined basal layer of columnar cells, an overlying layer that is often many cells thick and that may resemble stellate reticulum, and masses of 'ghost' epithelial cells that may be in the epithelial cyst lining or in the fibrous capsule." Here, we present a case report of a 21-year-old male patient with a calcifying cyst associated with an impacted left mandibular third molar.