This report presents a case of nonsurgical retreatment of an already apicected second mandibular premolar with asymptomatic apical periodontitis. Radiographic examination showed an insufficient coronal restoration, a poor root canal filling, a root-end filling and an apical radiolucency. Treatment was comprised of cleaning and shaping of the root canal, removal of the retrograde filling by ultrasonics and continuous irrigation, using calcium hydroxide as an intracanal dressing, and obturation of the root canal using mineral trioxide aggregate. At the 3.5-year follow-up, the tooth was asymptomatic and showed radiologically healthy periapical conditions. Schlagwörter: apicectomy, endodontic retreatment, MTA, removal of root-end filling, surgical failure