“Stripping” is lateral perforation is caused by overinstrumentation through a thin wall in the root and is most likely to occur at the inside wall of a curved canal, such as the distal wall of the mesial roots in mandibular first molars. In the past, poor prognosis for strip and furcation perforations was probably due to bacterial leakage or lack of biocompatibility of repair materials. However, the recent development in the techniques and materials such as mineral trioxide aggregate (MTA) has enhanced the prognosis for such cases. There is limited literature on use of MTA as an obturating material in the treatment of strip perforation. This study presents two cases of strip perforation that are successfully repaired nonsurgically using MTA with 2-year follow up. Cases suggest that MTA can be used as an alternative root canal obturation material for the treatment of strip perforation. The property differences between gray and white MTA are reviewed.