Abstarct: • The aim of the present research was to investigate the impact of memorable sports tourism experience on environmentally friendly behavior with the mediating role of sustainable intelligence and ethical commitment. This study is descxriptive-correlational and, in terms of purpose, applied, carried out using structural equation modeling. The statistical population of the research included all recreational tourists in the open spaces of Nishapur county; due to the uncertainty of the population size, the sample size was determined baxsed on the Klein rule (2011) to be 200 people. Sampling was done conveniently, and the questionnaires were electronically published in relevant groups and networks, ultimately collecting and using 235 completed and valid questionnaires for analysis. For data collection, Kim's (2010) memorable sports tourism experience questionnaire, Lim et al.'s (2017) environmentally friendly behavior questionnaire, Lee et al.'s (2021) sustainable intelligence questionnaire, and Woo et al.'s (2020) ethical commitment questionnaire were used. The results from the structural equation model indicated that the memorable sports tourism experience has a positive and significant effect on sustainable intelligence and also a positive and significant effect on ethical commitment. Moreover, the direct effect of memorable experience on environmentally friendly behavior was significant. The findings suggested that sustainable intelligence plays a weak mediating role in the relationship between memorable experience and environmentally friendly behavior, while ethical commitment had a stronger and more significant mediating role. Overall, the research results showed that memorable sports tourism experiences could enhance individuals' levels of sustainable intelligence and ethical commitment through activating cognitive and emotional processes, ultimately reinforcing environmentally friendly behaviors among sports tourists. Therefore, creating conditions and activities that lead to deep, meaningful, and lasting experiences in tourists can be used as an effective approach in promoting environmentally friendly behaviors in the sports tourism industry.