Islamic Banking is not something you can do as a "side business" therefore do not get carried away with these so called "Islamic Windows" by Conventional Banks, more so for international banks. The full Islamic Banks in Qatar are Qatar Islamic Bank, Qatar International Islamic Bank and the latest Masraf Al Rayan. Masraf Al Rayan is by far the largest and the latest of the three and has already made a mark in quality of service and profitability. Visit their main branch at Grand Hamad Ave and the branch at Al Sadd street to see for yourself.