This thesis examined stress and anxiety in sport from a number of different perspectives. It is written as a series of research papers (chapters). Before the research papers, a critical review chapter is presented on the research and theory relevant to stress and anxiety in sport. One of the issues to arise from the review chapter was the relative merit of multidimensional anxiety theory and catastrophe models. In multidimensional anxiety theory, it is unclear whether cognitive anxiety and selfconfidence are viewed as being conceptually independent or conceptually codependent. In higher-order catastrophe models, self-confidence is viewed as being conceptually independent of cognitive anxiety and is expected to moderate the interactive effects of cognitive anxiety and physiological arousal upon performance. One of the aims of Chapter 3 was to clarify whether cognitive anxiety and selfconfidence were conceptually independent. This was done by means of a metaanalysis that explored the relationships between cognitive anxiety and performance, and self-confidence and performance. The magnitude of the (positive) self-confidence mean effect size was significantly larger than the magnitude of the (negative) cognitive anxiety mean effect size. This offers evidence for the relatively strong influence of self-confidence upon performance. It also provides support for the conceptual independence of cognitive anxiety and self-confidence. In Chapter 4, the role of self-confidence was explored within a higher-order catastrophe model framework. This involved an exploratory segmental analysis designed specifically for exploring bias factors in higher-order catastrophe models. This analysis supported the moderating role of self-confidence within this framework. More specifically, the maximum cognitive anxiety x somatic anxiety interaction effect size was at a higher level of somatic anxiety for the high self-confidence condition, when compared to the low self-confidence condition. Another of the findings from the meta-analysis was the dearth of studies conducted with elite performers. The final research paper was an investigation of organizational stress within an elite environment. In view of its exploratory nature, this study was conducted within a qualitative framework. The major sources of organizational stress to emerge from the interviews with elite athletes were: selection, training environment, finances, nutrition, goals and expectations, coaches and coaching styles, team atmosphere, roles, support network, 111 and communication. A general discussion chapter follows the research papers. In this chapter, implications for future research and applied practice are discussed in relation to the project as a whole.