Indiana University-Purdue University Indianapolis (IUPUI) / Since the COVID-19 pandemic unexpectedly hit the world, the tourism industry has been impacted in every conceivable area. Environmental issues are recognized and considered essential to solve especially in the tourism industry. It is unavoidable that tourists bring both positive and negative impacts to a destination. Meanwhile, the tourism industry is eager to return to its pre-pandemic tourist numbers and levels of spending that traveler previously engaged in. The young generations, specifically Gen Y and Z, play an important role in the tourism market, and they often embody a mindset that takes into consideration issues of sustainability. However, they are not as active as expected in practicing sustainable travel behaviors. Sustainable tourism development and "green" travel practices are becoming increasingly necessary. The main purpose of this study is to identify the gaps between Gen Y and Z's intentions and their behaviors regarding sustainable travel. This study developed and tested a conceptual framework to understand this dynamic. This study identified two gaps: (a) the behavior-intention gap, which exists between Gen Y & Z's intentions and their behaviors in sustainable travel, and (b) daily life and sustainable travel gap, which is the gap between individuals’ daily sustainable habits and sustainable travel behaviors. The results of quantitative study indicated the factors contributed to the gaps included: (1) individuals who have bachelor’s degrees are more likely to conduct sustainable travel behaviors; (2) individuals who have daily sustainable habits; (3) individuals who have higher perceived consumer effectiveness. The implications of the study provide suggestions for destinations to promote sustainable travel and ways to encourage more sustainable traveling choices by travelers.