Thanks for the information, just one question when you get your Turkish driving licence do you get to keep your USA, UK one??

Let me get this straight: you think that attaining licensing in one country some how supersedes the sovereignty and license of a second country? Perhaps they take your old library card, too?

Italy used to make you surrender your UK license and Qatar still does

You keep your UK licence.

I got pulled over for a routine check the other day and for the first time was told my foreign driver's license was no longer valid. I tried to bluff that I was only here for a few months, but he didn't buy it (my children were speaking Turkish to each other in the back seat) and told me I could only drive on a foreign license for three months. He let me off with a warning.

Then, some jerk ran a red light and hit our car while my Turkish husband was driving. In order to be able to drive the rental our insurance company arranged for us to use until our car is repaired, they needed a copy of my driver's license and again I was warned that as a car owner and insurance carrier, I can no longer use my foreign license as it is clear I have been here for more than 3 months. Decided to look into it before anything else happens.

According to Istanbul's Department of Motor Vehicle Registration (Trafik Tescil Şube Müdürlüğü) website you need the following documents:
1-Your original foreign driver's license and a notarized copy of its Turkish translation (by a notary or consulate)
2-Application Form EK-18 (you get it from the 'Şöferler Odası')
3-Original Residence/Work Permit and one photocopy of it
4-Five photographs
5-Criminal Record (valid for one year)
6-Health Report (from a state hospital or a private hospital)
7-Blood type report
8-Receipt of payment for the relevant driver's license class (to be paid at the Maliye Dairesi or the Vergi Dairesi)

Note: Before preparing the above documents, the website recommends that you first go to the department of motor vehicle registration with your foreign driver's license and translation to see if you will need to get it renewed before applying or not.

Of course this is all theory at this point. I will let you know how reality looks when I get it done.