Since the past, the market has offered us various products and services. Especially the customers have always been an important of the seservices. Customer satisfaction has also been important in the past whether your services were also recommended to other people or not. So, in our diploma thesis we explored the perception of the mobile operator the 4. The main goal was the carry out the analysis of the mobile operator's customers, where the survey was focused on the selected tools of the marketing mix and communication channels. Partial objectives included information analysis and mobile operator surveys. The first chapter was devoted to the study of services marketing, marketing mix and the customer satisfaction. The second part of the thesis was to carry out marketing research and to process the results. In the conclusion, we discussed the causes of negative results and suggestion for improvement.