Aim: Taurodontism is a developmental anomaly characterized by a vertically elongated pulp chamber and an apically displaced pulp floor on radiography. The aim of this case report is to demonstrate endodontic treatment approaches in teeth with acute apical abscess with taurodontism. Case Description: A 19-year-old male patient applied to our clinic with severe pain. In the patient's anamnesis, it was observed that he had a preliminary diagnosis of ectodermal dysplasia. In the clinical examination of the patient, teeth with hypodontia, microdontia and taurodontism were detected. Extraoral examination revealed swelling and lymphadenopathy at the left mandibular jaw region of the patient. In the radiographic examination, deep caries and taurodontism anomaly were detected in the mandibular left first molar tooth of the patient. Cone-beam computed tomography scan was performed on the relevant area and it was observed that the tooth was a single rooted, single-canal, pyramidal molar tooth with a wide apical foramen. Root canal treatment was performed in the related tooth. In the first session, the chemomechanical preparation was completed and the patient was prescribed antibiotics. In the second session, the patient's symptoms decreased and calcium hydroxide was administered as an intracanal medicament. In the last session, it was observed that the patient's symptoms disappeared completely. To create an apical barrier, mineral trioxide aggregate was placed at the root apex and root canals were obturated with mineral trioxide aggregate. The coronal restoration of the tooth was completed and the patient was called for control session after one month. Results: During the follow-up examination of the patient, it was determined that the patient's symptoms completely disappeared and the tooth was in function. Conclusion: In teeth with acute apical abscess and taurodontism anomaly, existing teeth can be preserved and successful clinical results can be obtained with the correct indication and effective treatment.