Abstract: Most of the banks in Rwanda have undergone through the process of Merger and/or Acquisition in the recent past. The general objective of this study was to assess the effects of business merger and acquisition on bank financial performance in Rwanda. This study aimed to assess the factors that lead the merger and acquisitions in commercial banks in Rwanda, to assess the factors that determine the performance of commercial banks in Rwanda, to determine the relationship between merger and acquisition and the financial performance of banks in Rwanda.