The final paper shows the importance of after-sales customer satisfaction in the business of any company. The characteristics of successful companies and factors important for business (technological challenge, competition and consumer requirements) are described. Customers and their needs, customer satisfaction as the goal of the organization are determined, and customer satisfaction and consumer satisfaction as a measure are defined. The relationship between regular and non-regular consumers and the importance of after-sales activities are presented. Methods of monitoring customer satisfaction and a questionnaire are listed as the main instrument of satisfaction research. The need to introduce a CRM (Customer Relationship Management) system is emphasized in order to facilitate the continuation of business cooperation with the customer. After-sales service and after-sales satisfaction in the hotel industry are discussed through the example of the largest tourist company in Croatia - Valamar Riviera d.d. and Cefalu Resort Sporting Club, Sicily (which uses a semi-structured interview and critical incident method). Finally, the indispensable ISO 9000 Standards are listed.