An unusual presentation of dens invaginatus affecting a microdontic permanent lateral incisor in a 19-year-old female patient is reported and pertinent literature reviewed. The patient was referred to the oral and maxillofacial radiology clinic of the authors' institution for radiographic examination of her maxillary teeth. Dens invaginatus was identified on the maxillary right lateral incisor in the anterior periapical radiographs. The tooth was microdontic and clinically simulated a primary tooth. Dens invaginatus occurs rarely in primary dentition although it is fairly common in permanent teeth. Only 4 instances of dens invaginatus affecting the primary dentition have been reported in the literature. The etiology, pathophysiology, association with other dental anomalies, as well as management aspects of this common anomaly, are discussed.