This thesis aims to provide a deeper understanding of tourist behaviour in the context of a Long-Stay Holiday (LSH). Accordingly, variables of interest include tourist motivation, long-stay tourists, and relaxation, together with responses of mature-aged travellers in this situation. In this thesis, a mature-aged traveller is over 45 years and a long-stay is treated as being from 10 to 90 days. The site for data collection is Phuket, Thailand, one of the world’s most popular destinations for relaxation holidays, especially long-stay holidays. The research problem has been stated as: How do mature-aged international tourists behave during a Long-Stay Holiday? This research is important for several reasons. The growth in ageing societies worldwide demonstrates a greater opportunity for tourism industries to attract mature-aged individuals to travel more and stay longer (Chen & Shoemaker, 2014; Wong & Musa, 2014). The population aged over 60 years is expected to continue growing quickly and will make up over 20% of the population worldwide within another two decades (UN, 2015). Indeed, tourism industries are particularly interested in the senior tourist market as seniors and retirees often have more resources, such as time and money, for travel ( Jang & Wu, 2006; Sangpikul, 2008) and tend to stay longer (Alegre & Pou, 2006) than other age segments. Consequently, tourist destinations are keenly interested in long-stay tourism and a number of Asian countries have introduced specific Long Stay Projects to attract and retain long-stay tourists, especially mature-aged tourists. Thailand, Malaysia and the Philippines have all introduced such projects.