THE PURPOSE OF THIS PAPER IS TO DEVELOP AN OUTPUT ORIENTED METHODOLOGY FOR MEASURING PRODUCTIVITY CHANGES BY USING DATA ENVELOPMENT ANALYSIS (DEA) AND MALMQUIST PRODUCTIVITY INDEX (MPI), AND APPLIES IT TO FIVE NUMBERS OF IRANIAN COMMERCIAL BANKS OVER THE 5-YEARS PERIOD (2009-2013). IN THIS REGARD, MEASURING THE MPI WITH DEA FOR SINGLE PROCESS UNITS HAS BEEN RESEARCHED BY LARGE NUMBER OF AUTHORS UP TO NOW. IN THIS PAPER AND FOR EXTENDING THE ABOVE MEASUREMENTS TO THE TWO-STAGE PROCESSES, WE HAVE PROPOSED A MODEL FOR CALCULATING OF THE OVERALL EFFICIENCY OF TWO-STAGE PROCESSES VIA BOTH CRS AND VRS REFERENCE TECHNOLOGIES, AND COMBINED THEM WITH MPI’S DISTANCE FUNCTIONS FOR ACCESS TO THE TWO-STAGE DEA-BASED MPI CONCLUSIONS. FINALLY, WE HAVE EXAMINED THE RESULTS TO BANKING SYSTEM IN IRAN.