A perforation is an undesirable communication between the root canal system and the supporting tissues or both. In endodontics, root perforations are referred as the second greatest cause of treatment failure next to improper obturation. Many materials and techniques have been tried to repair the furcation perforation. The purpose of this study was to evaluate the sealing ability of mineral trioxide aggregate,resin modified glass ionomer cement and calcium phosphate cement to repair the furcation perforation. The results of the studydemonstrated that the microleakage was least when perforation was repaired with mineral trioxide aggregateand it was maximum when perforation was repaired with calcium phosphate cement.