Abstract. This research is intended to analyse the efficiency level of Islamic Bank in Indonesia, Saudi Arabia, and United Kingdom from 2015 to 2019. Calculation of the level of efficiency in this study is relative, not absolute. This study uses the Data Envelopment Analysis (DEA) method and source data from Bankscope and Bank Focus. This research consists of 3 input variables namely Total of Assets (X1) Staff Expenses (X2) and Total Deposit (X3) and 2 Output is Income (Y1) and Loan (Y2). This research finds that overall level of efficiency of Islamic bank in Indonesia, Saudi Arabia, and United Kingdom are fluctuating. According to the result, in overall Islamic bank in Saudi Arabia more efficient than in Indonesia and United Kingdom. There are some variabels that inefficient. The solution for this inefficiency problem can be achieved by employing managerial simulation generated by DEA.