Unsustainable use of natural heritage leads to their destruction. Nowadays, rivers, as one of the most vital natural heritage, have been used unsustainably. Generally, rivers have the ability to attract tourists in the long run. Therefore, a sustainable tourism approach can help improve rivers' conditions while attracting tourists. With the descriptive-analytical method and the purpose of analyzing the environmental aspects affecting sustainable tourism realization, Zarjub River, located in Rasht, was evaluated. Subsequently, through the analytical hierarchy process and a survey of 25 local experts, the importance of environmental criteria and sub-criteria was determined. In order to assess the current status of the Zarjub River according to the criteria and sub-criteria, available statistics and questionnaire tool were used. In this regard, 400 citizens, 25 local experts, and 20 municipal officials were surveyed. Statistical analysis was performed using SPSS. Then, according to the importance and the current status of the criteria and sub-criteria, an integrated analysis was carried out. All criteria and sub-criteria are in the second, third and fourth areas. The criteria in the second area are more effective in realizing sustainable tourism because of their high importance and unfavorable status quo. The SWOT strategies were ranked with the VIKOR method, based on the criteria and sub-criteria and with the help of 25 native experts. Among the strategies presented, the strategy of "strengthening the tourism aspect of the river in all seasons, based on the principles of sustainability" was ranked first in terms of importance.