Background and Aim: The tourism industry is a significant driver of economic growth, particularly in developing countries. Chiang Mai Province, especially Chiang Dao District, is a popular tourist destination in Thailand, known for its natural beauty, cultural heritage, and historical significance. This study aims to investigate the influence of marketing mix factors (product, price, place, and promotion) on the travel decisions of Thai tourists visiting Chiang Dao District. Materials and Methods: A quantitative research methodology was employed, involving a questionnaire survey of 385 Thai tourists visiting Chiang Dao District. Data analysis included descriptive statistics, correlation analysis, and multiple regression analysis. Results: The findings reveal that all four marketing mix factors significantly influence Thai tourists' travel decisions. Product, encompassing the overall destination experience, was found to be the most influential factor. Price, place, and promotion also played significant roles in shaping tourists' choices. Conclusion: This study underscores the importance of a comprehensive marketing mix strategy in attracting Thai tourists to Chiang Dao District. Tourism stakeholders should focus on developing unique product offerings, competitive pricing, enhancing the destination's ambiance, and implementing effective promotional campaigns to cater to the preferences of Thai tourists and ensure the sustainable growth of the tourism industry in the region