Invasive cervical resorption (ICR) is a rare external dental resorption with unknown etiology; it progresses asymptomatically in the cervical area of the permanent teeth. Lesions are mostly misdiagnosed as internal resorption or caries, which leads to erroneous treatments. This case report presents the clinical and radiological diagnosis, as well as the results of treatment and 3-year follow-up in a 50-year-old female patient with gingival enlargement associated with ICR in tooth No. 25. Granulation tissue was removed by accessing the cervical resorption area through a flap operation. Following the endodontic treatment, the tooth was restored using composite resin and the hyperplastic lesion was excised. In conclusion, it should be kept in mind that clinical, radiological, and pathological evaluation in the differential diagnosis of localized hyperplastic lesions in the gingiva is of importance and that ICR could play a role in the etiology of these lesions.