Wearing a traditional Thai cotton dress is getting popular, particularly among Generation Z, which has greater access to internet media than previous generations. It is inspired by online communities, soap operas, celebrities, and fashionistas. The study aims to determine which factors of the Marketing Mix (4P) consisting of price, product, place, and promotion influence the purchasing decision of Generation Z groups by using the Best-Worst Method (BWM) proposed for solving the issue of selecting the best strategy. The information was gathered from 400 students at the Mae Fah Luang campus. The results showed that the best factor influencing customer purchasing decisions is a product and the average weight is 0.3038. It shows the products that reflect the wearer's identity and it in line with current fashion trends are of the utmost importance. The second factor is price, which shows an average weight of 0.2817. Customers in Generation z focus on a reasonable price related to a limited income. Therefore, these two factors influence buyers more than other factors.