The world is currently dealing with severe environmental problems caused by human activities. This has led to increased awareness of sustainable behavior. Consumption plays a crucial role because consumers' choices directly affect the environment (Trudel, 2018). Sustainable consumer behavior is seen as the main solution for environmental issues in the hotel industry, and the growing focus on sustainability and sustainable lifestyle has influenced consumers to adopt more environmentally friendly consumption behavior (Bashir et al., 2019). This qualitative thesis explores young Finnish adults' environmentally sustainable consumer behavior through customers' perceptions during leisure hotel stays abroad. Seven semi-structured interviews with participants aged 21 to 26 were conducted, exploring three research questions (RQs): RQ1. How aware are young adults of environmentally sustainable consumer behavior when using hotel products and services abroad? RQ2. How responsible are young adults in terms of environmentally sustainable consumer behavior when using hotel products and services? RQ3. What challenges affect young adults' environmentally sustainable consumer behavior when using hotel products and services abroad? The main findings from the study include, for example, that the participants had anawareness of their ESCB but did not fully embrace it and showed less responsible behavior while at a hotel than at home. The changed environment significantly influenced them, leading them to a less environmentally sustainable mindset. The thesis is organized to present chapters, including the following: 1. Introduction, 2. Literature review, 3. Methodology, 4. Findings and discussions, and 5. Conclusion.