Radicular cyst is the most common odontogenic cyst of the jaw; however, its association with overretained deciduous teeth involving impacted permanent teeth is a rare entity and hence may pose a diagnostic dilemma. The aim of this report is to present a case of radicular cyst that mimicked the dentigerous cyst. A 31-year-old female reported to the department of oral medicine with the chief complaint of swelling on the lower left side of the face. Intraoral examination revealed over-retained carious 75. Based on the clinical features, differential diagnosis was given as a radicular cyst and a dentigerous cyst on radiographic examination; intraoral periapical revealed a cystic lesion involving the crown of the deciduous tooth. Cone-beam computed tomography further confirmed that the cystic lesion was not involving the crown of the impacted premolar. Hence, the three-dimensional radiographic evaluation of the lesion helps to rule out the differential diagnosis.