Smoking is banned in all public places in Qatar. This is the law. Unfortunately it is not enforced and lots of people in cafes, etc carry on smoking. Many people who smoke will not follow the instructions of the staff or security who ask them to stop. I personally do not wish to breath in someone else's smoke and tell people all the time to put their cigarettes out and point to the no smoking sign. I've never had someone refuse me but that's usually after I have mentioned it to staff/secirity and they have not been listened to. I think Qatar won some kind of award for introducing this law. It's such a pity it's not properly enforced.