[Truncated abstract] Global tourism accounted for US$623 billion in 2004, representing 6% of the world's exports of goods and services (World Tourism Organisation, 2005). In the last decade, natural and man-made disasters have adversely affected the tourism industry. Consequently, the risk and uncertainty associated with travel have increased, potentially impacting on tourists' behaviour. However, while travel motivators have received a great deal of research attention, travel constraints have not been examined to the same degree. The present study explores risk and uncertainty and their roles in people's decisionmaking processes in a tourism context. In doing so, attempts were made to clarify the distinction between the risk and uncertainty constructs, which in prior research often have been used interchangeably, leading to some confusion about their roles. The distinction between the perceptual and attitudinal constructs also was clarified, as prior research into their differential impacts has been limited. To achieve these objectives, data were collected from online research panel members in Australia, the United States (USA), the United Kingdom (UK), New Zealand, South Korea, China and Japan, as part of a larger tourism study. While the majority of the country samples were drawn from the general population, the Japan sample constituted an international