The purpose of the present study was to explore the factor structure of a positive personality trait known as Grit and investigate its predictive validity for achievement outcomes. Grit is defined and organised in a self-report scale in terms of two factors: Consistency of Interest and the Perseverance of Effort towards long term goals (Duckworth et al., 2007). Grit correlated positively to broad and narrow measures of Conscientiousness and negatively to those of Neuroticism. Exploratory factor analysis indicated divergence of the two factors, where they came to represent two different facets of Conscientiousness. Grit did not show incremental validity over broad and narrow measures of Conscientiousness in predicting high school GPA; however the subscale for Grit perseverance did show incremental validity over Conscientiousness in predicting long term achievement