Objective: The purpose of this case report is to introduce a minimally invasive microsurgical technique for the treatment of the necrotic, immature apex tooth in adult patients and to provide treatment recommendations. Method and Materials: A 43-year-old male patient was diagnosed with chronic apical periodontitis associated with a necrotic, immature apex of the maxillary central incisor. A minimally invasive microsurgical approach was applied for the treatment of the periapical disease. The crown of the immature apex tooth was left intact. Results: The 1-year follow-up radiograph revealed uneventful healing of the periradicular lesion while soft tissue healing was optimal. Conclusion: The minimally invasive microsurgical technique may provide a viable solution for the survival of challenging necrotic, immature apex tooth cases in adults. Proper case selection is mandatory for the success of this technique. Schlagwörter: immature apex, microsurgery, minimally invasive