High unemployment rate in Iran has brought about some national projects of which one is Small and Medium Enterprises (SME) Credits. A main sector that uses SME credits is handmade carpet industry. The main purpose of this study is to investigate the effectiveness of SME credits in East Azerbaijan, Khorasan Razavi and Qom provinces of Iran. Investigating factors associated with effectiveness of SME credits were income, cost, profit, labor and production of carpet weaver households for the years 2006, 2007 and 2010. The effectiveness of SME credits was evaluated using matching estimators. To achieve the purpose, the statistical population was divided into two groups of Control (carpet weavers who do not used SME credits) and Treatment (carpet weavers who used SME credits) group. Sampling performed through simple random sampling in each group. The results show that SME Credits had no significant impact on the income, cost, profit, labor and production of carpet weaver households in Khorasan Razavi and Qom provinces; however in the East Azerbaijan the credits had significant impact on the mentioned variables.