We stayed here for 4 nights last month and would look further next time. Room was very small, no place for luggage, and impossible to use the toilet without first shutting the door. Many narrow steps up to rooftop area where breakfast served. Food was OK, not excellent as many reviewers state. Lovely family running the guesthouse. Limited English other than the daughter. Best part was the location and the restaurant Aloran 2 blocks away.

The Marmar Guesthouse is so close to all the sights in Istanbul. The rooms are great and there is always hot water. The hosts (Effie) is very friendly and always willing to help out with everything. The only downside is there is no elevator. The terrace on the roof is awesome and has a great view of the bay. Overall I would definitely recommend the Marmara Guesthouse. Also it's on a little street just off a main street so it's pretty quiet.

We found Marmara Guesthouse through the Lonely Planet Guide, and everything they said is true.
Elif Aytekin and her family make you feel very welcome and comfortable. The rooms are small, but very clean and have everything you need for a good night's sleep. The breakfast's are delicious and you have a beautiful view of the Marmara Sea from the vine-covered rooftop terrace. It is located in a great part of Sultanahmet, close to most of the major sights. Great value for the money.

excellent location, charming rooms, clean and air conditionned. Great view from the terrace on Bosphorus, (unforgettable breakfasts!)
The team is adorable and very helpful.
I would sincerely recommand this place to my friends.