Throughout the dental history, a wide variety of materials have been used for retrograde fillings and perforation repair. All of them have some or other problem that limits their use in endodontic procedures. Mineral Trioxide Aggregate or MTA, a biocompatible biomaterial developed by Torabinejad et al is a mixture of refined Portland cement, gypsum and bismuth oxide. The properties of this material come closest to the requirements for an ideal endodontic repair material. MTA is reported to have numerous clinical applications in the field of endodontics. This text provides coverage of all aspects of this biomaterial including its properties, manipulation, biocompatibility and clinical implications. All the latest recommendations are included along with comprehensive discussions. Attempts have been made to extensively cover every aspect of this material through pictures and flow charts which are formatted in easy to follow manner.