The growing emphasis on sustainability within the hotel industry underscores the need for rigorous sustainable management practices. This study aims to assess and evaluate the extent to which five-star hotels in Portugal have implemented sustainable management practices, addressing the critical need for alignment with industry-recognized standards. Utilizing a quantitative content analysis approach, the study employs criteria from the Global Sustainable Tourism Council (GSTC), Green Key, and Green Globe to form its analysis framework. The official websites and available information of 175 five-star hotels were reviewed to identify the presence of sustainable management practices. The analysis reveals low levels of compliance with the established sustainability criteria across various areas, including sustainability management systems, legal adherence, and disaster management. While some hotels demonstrate efforts in engaging staff and stakeholders, and in promoting sustainability, overall compliance remains limited. These findings highlight significant gaps and underscore the necessity for increased education, resources, and support to reinforce sustainability efforts within the Portuguese hotel sector. Addressing these challenges can enhance the alignment of hotels with global sustainability goals, improve their competitive edge in the sustainably conscious market, and contribute to the broader sustainability of the hotel industry. This study provides valuable insights for hoteliers, policymakers, and researchers dedicated to advancing sustainable hotel practices.