A supernumerary root is a developmental condition occurring due to disturbances in the Hertwig epithelial root sheath. Supernumerary roots are rare in primary mandibular molars, and the etiology is uncertain. However, it is crucial for dental practitioners to be aware that extra roots may be present in primary teeth and provide accurate diagnosis when they occur. An extra root or canal that is not identified during endodontic treatment can lead to treatment failure. The present report describes 2 cases of primary mandibular second molars with supernumerary roots showing carious involvement. In one of the patients, the molar had 2 supernumerary roots and was treated successfully by pulpectomy. In the other patient, the molar had 1 supernumerary root. The tooth was extracted, and a space maintainer was placed.