Efficiency evaluation has long been an issue of great concern for the banking sector (financial institutions and for the banks themselves). This is particularly the case for State financial institutions which can be able to act proactively and prevent severe turbulence in the market. That is a very important task in a small market where operates a large number of banks, such as the Serbian market. The aim of paper is to present new way in calculating efficiency using data envelopment analysis (DEA), as the most widely used efficiency evaluation method. We present a novel approach in obtaining weight restrictions for DEA, based on the bootstrapping distance based analysis (DBA). Analysis was conducted on 29 banks, which have been operating in Serbia during 2010.