This study aims to explore the behavior of tourists in choosing street food in the Mueang district of Surat Thani province, Thailand. Data was collected through a questionnaire from 400 tourists, both Thai and foreign, who visited the Mueang district. The sample size was determined using Cochran's formula at a 95% confidence level, using non-probability sampling and purposive sampling. Descriptive statistics used included frequency, percentage, mean, and standard deviation. Inferential statistics applied were ANOVA and multiple regression. The results revealed that factors related to the marketing mix and psychological aspects were generally considered significant. In terms of street food purchasing behavior, most tourists visited 6-10 times primarily to consume single-dish meals such as rice dishes, noodles, Pad Thai, fried mollusks, rice noodles, etc. Moreover, tourists tend to buy food between 15:01 to 18:00 and usually dine with friends. The majority spent between 501 to 1,000 baht per meal and relied on Google as their primary information source. Hypothesis testing showed that: 1) Personal factors significantly influence tourist behavior in selecting street food in the Mueang district. 2) Marketing mix elements significantly correlate with this behavior, notably in terms of promotion and service processes at a 0.05 significance level. 3) Psychological factors, especially motivation and learning, also play a significant role at a 0.05 significance level.