The decline in children's connection with nature is one of the global challenges in recent decades. The growing trend of urbanization, changing lifestyles, and dependence on digital technologies have caused children to spend less time outdoors and lose the opportunity to directly experience natural environments. Despite numerous studies on children's connection with nature, the factors affecting the transfer of nature tourism experience to environmentally responsible behaviors in children have not been studied much, especially in the context of tourism experience. The present study was designed to explain the relationships between memorable nature tourism experiences, environmental knowledge, and environmentally responsible behaviors in children. In this study, 406 questionnaires were collected from 9- to 12-year-old children with nature tourism experience using a non-probability sampling method. The research instrument included items to measure each of the model constructs, the validity and reliability of which were confirmed by statistical methods. Smart PLS software was used to test structural equation modeling and SPSS was used for descriptive and preliminary analyses. The findings showed that memorable nature tourism experiences have a positive and significant effect on children's responsible environmental behavior (β=0.462), (p<0.001). The mediating role of environmental knowledge in these relationships was also confirmed. This means that the higher the level of children's environmental knowledge, the greater the effect of memorable nature tourism experiences on their responsible behaviors. The results of the study emphasize the importance of designing educational and nature tourism programs for children, especially programs that provide opportunities for direct interaction with the ...