i stayed there with my wife for 3 nights.
we had great expectations about this hotel. it is consider to be one of the most luxurious and finest hotels in greece but unfortunatelly this was a myth!
the room was classical in decoration but small not very properly cleaned and the furnitures were in bad condition full of scratches. the wall paper(must have been wonderfull)was very dirty with stains. we were mostly surprised of the size o the bathroom. it was vey-very small(it was the smallest bathroom i have ever seen in a 5 star hotel)although the bathroom amenities were plenty. the carpet of the room was very dirty and old with stains everywhere.
the radio did not work, there was no internet connection or pay t.v. sevice which i believe in a 5 star hotel is a common thing.
the door was not sounproofed and you could hear people's voices when they were passing outside of your room(difficult to sleep. the cupboard was very old and small.
the restaurants were o.k. and generally the food was very tasty. the bar was very stuffy and the lobby uninviting. the employers were friendly but not professional. you could never find a bell-boy to carry your luggages and one of the receptionists once helped us with our things.
generally it is a hotel that it is not in a good condition everything needs to be repaired and re-organized. we love classical style hotels but only when they are well maintained not this old and tired like for a horror movie hotel. because of all this problems all the charm and elegance were lost.
if you pay (as we did)around 300 euros per night (official rate 890 euros!!!)you expect that everything will perfect a word that does not belong to the vocabulary of the owners i think!

My wife and I stayed for 4 nights at the Pentelikon on combined business/pleasure. It was a superb hotel, with friendly, understated service. Kifissia and the local area is pleasant to walk around and apparently significantly cooler than central Athens in high summer. The nearest metro station is 15 minutes walk away (downhill to get there, but uphill at the end of the day!)We didn't eat at the restaurant but I'm sure it lives up to its reputation. There's also a great outdoor pool at the Pentelikon, and this would make an excellent base for a family to explore Athens - away from the city centre bustle, but within easy reach of everything.

I have been staying in this hotel for weeks in this hotel for business reasons and I find it very good.
After my wife visited me for a few days and stayed at the hotel, she wanted to go back for hollydays because of the hotel but also because of the staff which is very helpfull.

Will definitely come back.

This is a cozy hotel which is actually located in Kifisià, a very quiet and "très chic" residential area about 10 km north of Athens. Excellent service and old-styled rooms, which are anyway in pristine conditions, makes this hotel somewhat different from the common, American style first class standard.

I think it is a very good choice if you wish to relax far from the bustiling chaos of Athens, however do note that the Pentelikon is far away from the major tourist attractions of the city. Also, in my opinion, it is also slightly overpriced.