Many root end filling materials for apical surgeries have been identified either for scientific evaluation or clinical usage but none meets the requirements of an ideal root end filling material. Recently a new cement, Mineral Trioxide Aggregate (MTA) was researched as a potential root end filling material and showed promising results. This paper reports the significant findings of research done on MTA as a root end filling material and presents a clinical case where apical surgery was performed using MTA as retrograde filling.