This paper investigates the relationship between interbank funds and efficiencies is for the commercial banks operating in Turkey between 2001-2006. Data Envelopment Analysis (DEA) is executed to find the efficiency scores of the banks for each year, and fixed effects panel data regression is carried out, with the efficiency scores being the response variable. It is observed that interbank
funds (ratio) has negative effects on bank efficiency, while bank capitalization and loan ratio have positive, and profitability has insignificant effects. Our study serves as an illustrative evidence that interbank funds can have adverse effects in an emerging market