Economic growth along with inflation and unemployment are the main topics discussed in macroeconomics. Achieving a suitable economic growth rate and permanent development are among the most important duties and goals of managers, economists, policy makers and etc. Observing that banks are capable of attracting people's small or great savings which are generally still by absorbing types of deposit also, are capable of using these aggregated resources in productive economic sections and accelerating economic growth process therefore, investigating the relation of banks' endowed credits with economic growth has a particular importance. The present study investigates and evaluates the effect of endowed credits of specialized banks and economic growth in Iran using the data of time series, work force mass, endowed credit mass of specialized banks and, real gross domestic product (GDP) mass during 1997 to 2012. Specification model used for analyzing data in this study is Auto Regressive Distributed Lag (ARDL) method as GDP is a function of endowed credit mass of banks as the substitute of capital and work force in Iran. Results of this study show that endowed credits of specialized banks in Iran has the potential of affecting economic growth in long term and short term but its relation with economic growth in long term is more effective and strong. Results of experimental tests show that these variables satisfy the economic prerequisite also; all of the variables in long term and short term are statistically meaningful and the considered pattern for investigating the relationship between the variables is also constant and convergent.