The development of tourism as a strategic and structural sector of our economy is strongly dependent on the quality of services in the hotels. The aim of this survey is to assess the quality of service in four-star hotels in Bulgaria, to reveal the omissions in this activity and based on that, to identify and take measures to improve the services in these hospitality premises. In the current research, three key stages of service in the hotel are outlined: check-in reception services, service during stay; check-out services. For the right service rating, these criteria are set up through separate indicators, which are thoroughly examined. In this sense/ respect, the quantification of the criterion, reception services, is performed by the following service indicators: during reservation, check-in and accommodation. The evaluation of the criterion service during stay, was conducted by means of the following indicators: room service for the over night stay, in the restaurant and ongoing service. The third criterion for service at check-out, the following indicators were evaluated: customer service at the reception upon check-out and customer satisfaction feedback. The results of the survey conducted by us, show that in most of the surveyed four-star hotels, the quality of service found does not correspond to the category of the hotel, despite the magnificent facilities available. The basic characteristics of quality have been achieved and customer expectations have been partially satisfied, but the so specific attention to guests has not been paid during the service. Although there is satisfaction with the services, where specific needs and desires have been taken into account, this satisfaction is so insignificant that it does not influence very much the choice of the same hotel in subsequent accommodation. This article has expressed a practical-executive focus. Measures for improvement were outlined based on the deficiencies in the activity of customer service.