The current research was conducted with the aim of investigating sustainability solutions in Kermanshah city. The research is of a qualitative type and was conducted using interview and questionnaire tools. The community studied in the qualitative section, including all the articles, books and reports available from 2010 to 2021 about the length of stay and key informed and expert people, university professors in the field of management and tourism and managers of tourism service offices. Sampling was selected theoretically and with the benefit of targeted (judgmental) and available techniques. The criterion for selecting the sample size in the qualitative section was theoretical saturation, which is 20 people. Data collection tools are in-depth and semi-structured interviews and questionnaires. According to Holsti's reliability formula, the number of 76% was obtained, which indicates the reliability and trustworthiness of the tool. Data analysis was done using qualitative (thematic) content analysis method. The results of the inductive content analysis of the data obtained from the interviews, through the three procedures of categorization, conceptualization, and coding, resulted in the identification of 168 codes, 43 concepts, and 15 categories, based on which factors, obstacles, and solutions to increase sustainability in Kermanshah city were identified. Also, the identified factors affecting retention were prioritized using the Delphi method, and these factors, in the order of priority, include destination attractions, socio-demographic characteristics, and travel characteristics.