Objective: The purpose of this study was to compare and evaluate the efficiency of pulp revascularization and MTA apexification; in patients with necrotic immature anterior teeth with periapical abscessMaterials and Methods: in this randomized controlled clinical trial, twenty-two necrotic immature anterior teeth of patients 7-16 years old were divided into 2 groups: Group (A) Regeneration “blood clot initiation” and Group (B) MTA- Apexification. The first visit was accomplished by using NaOCL irrigation and intracanal medication with TAP without instrumentation in both groups. Follow-up was done up to 9 months using standardized digital radiographs. Results: showed that there was no statistically significant difference between the two groups in the root width and length except in the percentage decrease of apical diameter due to the hard tissue barrier formed in 5 cases (5/10) with (p=0.029) in the apexification group. Conclusion: Both treatment protocols (MTA apexification and pulp regeneration) were successful treatment options for necrotic immature teeth with regard to the healing of the periapical lesions and the apical closure.