A substantial body of research suggests that young people's emotions -- both positive and negative -- are linked to a wide range of future outcomes. This paper contributes to this literature by investigating the link between young people's positive and negative emotions and their performance in high-stakes examinations. Using Programme for International Student Assessment (PISA) data from England linked to the National Pupil Database (NPD), I investigate how 15-year-olds positive affect, negative affect and fear of failure is associated with the grades they achieve in high-stakes examinations. I find that low levels of positive affect -- i.e. pupils rarely feeling happy, lively and cheerful -- is associated with a 0.10-0.15 standard deviation reduction in young people's examination grades. On the other hand, little evidence is found of a substantive link between negative affect or fear of failure and examination performance.