This study examines the relationship between personality and two different academic performance (AP) assessment methods, namely exams and coursework. It aimed to examine whether the relationship between traits and AP was consistent across self-reported versus documented exam results, two different assessment techniques and across different faculties. There were 1,013 (622 female) university students from four British Universities in four faculties namely arts/humanities, social sciences, life/biological sciences and mathematical sciences. Participants completed a brief version of the Big Five inventory and a self-report measure of AP. Conscientiousness and Agreeableness were the strongest personality predictors of AP. Structural equation model showed that sex and personality effects on AP were invariant across different areas of study or degree types (humanities, social sciences, life sciences and hard sciences). Personality variables are stable, robust and predictable correlates and determinants of AP. Conscientiousness, Openness and Agreeableness were positive predictors as measured by good grades whilst Neuroticism and Extraversion were correlates of weaker performance. Implications of these results refer how teachers choose to examine their pupils and to what extent students choose courses because of their known examination procedures.