In recent decades, the market for organic products has grown tremendously throughout the world, derived from an awareness of environmental problems and concerns about the health and food safety of modern agricultural practices. Despite Thailand???s increases in organic production and consumption, the growth is still small and in the early phase of the development. The information about consumers??? purchasing behaviour towards organic products is not well researched in Thailand. This study investigates the important factors in consumers??? decisions to purchase organic products (such as vegetables and rice). In addition, this study aimed to estimate the mean willingness to pay (WTP) for organic products (such as Chinese kale, jasmine rice and pork) and assessed the important factors affecting the consumers??? WTP a price premium for organic products. A self-administered questionnaire was used to collect the data at five retail stores in Bangkok and metropolitan area. The survey data were analysed using exploratory factor analysis, logistic regression and double-bounded contingent valuation method. The results show that some respondents have been purchasing organic products but few purchased organic products on a regular basis. Respondents are more likely to purchase organic products if they are female, highly-educated, in middle-age, had knowledge about organic products, often purchase groceries at natural/health food store, concern about health and food safety, and perceive the benefits of organic products associated with quality, health and environmental friendly attributes. However, the respondents who are concern with the high price and limited availability and information about organic products are less likely to purchase organic products. The results of the WTP estimates suggest that respondents are willing to pay a premium price of 88%, 51% and 51% for organic Chinese kale, organic jasmine rice and organic pork, respectively. In addition, the respondents are willing to pay a premium price for organic products if they have experience in purchasing organic products, have good health, ethical and environmental concerns, perceive the quality and health benefits of organic products and resided in the city. On the other hand, respondents with children in the household are less likely to pay a premium price for organic products.