Many studies on bank efficiencies and productivity have been conducted but, to-date; a wide gap exists and few have referred to banks in Arab Gulf Cooperation Council (GCC) countries. Also the fact that commercial banks play a vital role in the economy, evaluating their overall performance and monitoring their financial condition is important to depositors, owners, potential investors, managers and, of course, regulators. In addition, to examining the theoretical aspects of technical efficiency and determinants of productivity, this book makes two contributions. First, in terms of empirical investigation, this is the first cross-country study investigate technical efficiency and productivity in the banking sector in GCC countries by analysing data pooled from six countries for ten years 1993-2002. Second, its findings would assist and guide commercial and Islamic banks’ managers as well as policy makers and regulatory authorities in ways to minimise inefficiency in the banking sector in order to realise a number of benefits.