This research paper, "Exploring the Key Factors Influencing Consumer Choice of 5-Star Eco-Friendly Hotels in Kolkata," analyzes the factors that determine consumers' choices while selecting sustainable hospitality services. It determines the most influential factors leading to the increase in demand for eco-friendly hotels and provides recommendations for the hospitality sector to incorporate more green elements into their services. Primary data were gathered through a systematic questionnaire grounded in literature reviews and expert opinions, sent through Google Forms to the visitors who had stayed at eco-friendly 5-star hotels in Kolkata. A total of 200 questionnaires were sent, out of which 132 were usable. Descriptive statistical measures such as weighted mean were used to rank factors of influence. Results indicated that consumer decisions are highly driven by green education, water saving, and appropriate waste disposal. The research emphasizes the necessity of measurability and transparency in sustainability practice. It argues that transparent, visible eco-initiatives are necessary to pull in green-aware visitors and induce sustainable tourism.