The aim of this thesis is to explore the relationship between anxiety on Working Memory (WM) performance and academic achievement. Research has highlighted negative effects of anxiety on cognition showing effects on both WM performance (e.g. Shackman et al., 2006; Schoofs et al., 2008) and academic tasks (e.g. Gumora & Arsenio., 2005). Research has aimed to understand the conditions under which anxiety impacts on cognition through considering the role of different threat manipulations on the interrelationship between anxiety, WM and academic performance (e.g. Owens et al., 2008). This has led to further research examining the role of implementing universal anxiety based interventions and WM skills training within both clinical and non-clinical samples to counteract the negative impact of anxiety on school performance. Following previous research (e.g. Shackman et al), the current thesis highlighted that spatial WM was selectively impaired by a physical threat in those who experienced increased levels of physiological arousal (study 1), and levels of worry impaired verbal WM under the same threat (studies 1 and 2). In addition, verbal WM was selectively impaired when individuals with increased levels of worry experienced a social threat (study 3). Both CBT interventions and WM training was shown to improve WM and academic performance (study 4) and CBT treatments decreased the level of anxiety and worry experienced (study 4). With future research in mind, considering the benefits of implementing universal CBT and WM treatment programmes to reduce the detrimental effects of increased anxiety and poor working memory on academic performance is crucial for young people to achieve their best in an academic environment