This research aimed to study about international tourists’ behaviour and factors affecting their decision-making on health and wellness activities using in Thailand by investigating from 397 questionnaires in Hua Hin, Thailand, and analysing with descriptive statistics. The results indicated that almost of respondents were male, came from UK. Their education level was bachelor degree and worked as business employee. Their monthly income was between USD 2,000 – 2,499. Their travelling motivation was for relaxation. Almost of them were first-time visitors and spent more than 10 nights in Thailand. 23.9% of them experienced health and wellness activities in Thailand, and around 41% used spa activity. Factors affecting their decision-making on health and wellness activities using were 1) health treatment and service factors such as modern technology and medical equipment, results of health and wellness services, international accreditation and hospitality services at strongly-agree level; 2) pricing factors such as costs of health and wellness services cheaper than home country and package payment for all treatment procedures and services at strongly-agree level; 3) distribution channel factors such as ability to access information and professional medical tourism agencies/facilitators at strongly-agree level; and 4) promotion and supporting factors such as easy border crossing/arrivals and consulate/immigration support at strongly-agree level too. Moreover, 86.6% of respondents would exactly revisit Thailand. This research results were significant database benefited Thailand health and wellness tourism promoting in international level and raised competitive capability as international hub of health tourism in the future.