The radicular cyst is the most common inflammatory odontogenic cystic lesion of the jaws. It usually originates as a sequel to a periapical inflammatory process, following chemical, physical or bacterial injury. Due to its chronic etiology, the cyst usually appears towards the later stage of life. It has a male sex predilection, with the maxillary anterior region as the most common site of involvement. This article reports a rare case of a large radicular cyst in the mandible, its management and follow up along one year.