This study evaluated the reliability and factor structure of the NEO Five-factor Inventory (NEO-FFI) among a sample of Australian adolescents (N = 459). With the exception of openness, the factors had good internal consistency. Item-level factor analyses using varimax and oblique rotation were used to examine the factor structure of the NEO-FFI. Visual inspection of the factor structures revealed a pattern that gave preliminary support for the five-factor model. However, statistical indices for factor structure did not support a five-factor model. Items for Conscientiousness and Neuroticism had the highest factor loadings and the fewest conflicting cross-loadings on the other factors. The discussion focuses on the importance of external validation of the traits from the five-factor model with other behavioural indicators.