This hotel is advertised as five stars. It is a complete mystery how this can be a five star hotel; the rooms are OK-ish but the bathrooms are more at the level of a two star hotel with blocked sinks, worn out bath tubs and poor lighting. They looked as if they were last re-furbished in the early 80-ties. When we stayed there the pool and all the spa part was being refurbished.
The receptionists were helpful and friendly. However, the main waiter in the restaurant on the top floor is pushy and unpleasant. He accepted our order of a portion of pasta with tomato sauce for our two children (half a protion each) which was not on the menu, and a plate of chips with a Milanese (battered veal escalope) but to our dismay we were charged extraordinary amounts of money for each (the milanese with chips cost more than any fancy main course on the menu; and similar charges were given to the simple pasta dish). Explanation: they were not on the menu and hence the extra costs??!! Having said that, I must admit that the food was delicious which is a credit to the restaurant's chef.
Another disappointment was the breakfast: again more like a two star hotel than a five star one.
My overall recommendation is: do not go there to stay! The restaurant is good but stick to what is on the menu!

Clean, welcoming, comfortable hotel with welcoming staff. We arrived at 10.40am and booked in without delay. The first thing we did was to take in the view from the rooftop restaurant. As we entered we were offered coffee and a table overlooking the Adriatic and the City of Trieste some 3km distant. A delightful welcome. One evening we asked at reception if the indoor pool was available and they immediately opened it up for the use of the two of us. Excellent breakfast and delightful situation - 5stars

It is a mystery how this hotel can be classified as 5 star. Location is on the noisy main road to Trieste centre with no parking. There was no views from my 2nd floor room except the builing across the main street. Room was very ordinary with a basic bathroom which must have been renovated more than 25 years ago, basic furniture and uncomfortable pillows. No internet access in my room, signal was far too weak. We had dinner in the top floor restaurant the day of our arrival, views are great, food OK but the head waiter was unfriendly and pushy. Breakfast usual Italian style buffet. For a price of EUR 150 I really had expected much more.

I was happily surprised after many searches for a great experience to rediscover my families city. The Maria Theresa was a little more than a walk to the center of Trieste, but still quite convenient by taxi or bus. The surroundings were of fine taste and service wonderful. Also, the breakfast on the terrace is never to be forgotten.
I arrived during an otherwise slow tourist season, and, in fact, quite happy I did. The staff was accomodating and friendly and even went beyond service by finding a small Slovenian community, not on a map, that was very important for me to visit.
The Maria Theresa is as a bejewelled music box, wanting to be discovered. I am so hoping Americans do find this, as well as Trieste on their map of places to visit.