Introduction: The purpose of the study was to compare the effectiveness of pulp revascularization and MTA apexification in the treatment of necrotic anterior teeth with periapical abscess. Methods: twenty-two patients, each with necrotic immature permanent anterior teeth were randomly divided into 2 groups (Group A apexification and group B regeneration) 11 patient per each group. A triantibiotic paste (metronidazole, ciprofloxacin and doxycycline) was used to disinfect the canal for 21 days. MTA plug was used for apexification for group A. Blood clot regeneration was used for the group B. The patients were recalled periodically for follow up.Results: The regeneration group showed better results in, increase in root length, increase in dentin thickness in mm, and in percentage, while MTA apexification group showed better results in decrease in apical diameter in millimeter.Conclusions: Both regeneration and MTA apexification are reliable procedures for treating necrotic immature anterior teeth with open apices.