The book studies the efficiency of the Islamic banking sectors in 25 countries during the period of 1992-2009 consists of 78 Islamic banks involved. The efficiency estimates of individual banks are evaluated using the non-parametric Data Envelopment Analysis (DEA) method. The empirical findings seem to suggest that the World Islamic banks have exhibited high pure technical efficiency. A multivariate analysis based on the Tobit model reinforces these findings and significantly associated with operating expenses against asset, size, equity, NPL, Asia Financial Crisis and national income level (GDP). We also find positive correlation between bank profitability and technical efficiency levels, indicating that the more efficient banks tend to be more profitable with strong result at Asian Islamic banks. The profitability analysis by Fixed Effect Model (FEM) proposed that profit efficiency is positively and significantly associated with operating expenses against asset, equity, high income countries and non performing loans against total loans specifically for model 8 & 9 that positively at 1% level.