The aim of the study was to report on the clinical and radiographic assessment of 38 cases of apexification using MTA over a three year period. Thirty-eight cases of immaturely developed teeth requiring endodontic therapy were treated using MTA to achieve an apical barrier prior to obturation with gutta-percha. The teeth were clinically and radiographically assessed. The findings indicate that apexification using MTA is a predictable procedure. In particular, the number of visits and the total time taken to achieve an apical barrier was markedly less than conventional techniques using calcium hydroxide. The presence of a preoperative periapical radiolucency had no effect on the outcome. MTA shows promise as a viable alternative to calcium hydroxide to achieve root-end closure and using MTA, the number of visits to achieve a successful apical barrier may be markedly reduced. The presence of preoperative periapical radiolucencies did not affect the outcome or the treatment protocol.