Measuring the productivity of banks, accompanied by analyzing and comparing their performance, have important roles in improving their productivity and efficiency so that they make up the backbone of the plans of banks. Initially, the Malmquist Productivity Index (MPI), one of the indicators of productivity measurement, is introduced. Hence, the paper describes how to obtain this index using the Data Envelopment Analysis (DEA). Then, the performance of Mellat Bank branches in Lorestan province is evaluated using the MPI to identify the efficient branches and the critical indicators of each branch, in order to increase their productivity Manuscript profile