This study examined the contributions of the 5-Factor Model (FFM; P. T. Costa & R. R. McCrae, 1992) and RIASEC (J. L. Holland, 1994) constructs of consistency, differentiation, and person-environment congruence in predicting job performance ratings in a large sample (N = 514) of employees. Hierarchical regression analyses conducted separately by gender indicated that the interaction of differentiation with Agreeableness and Conscientiousness explained statistically significant variance in work performance for men, and that the interaction of congruence with Agreeableness, Artistic, and Social subscales was statistically significantly related to work performance in women. Findings suggested that the most successful model of job performance prediction would be substantially more complex than simple RIASEC or FFM approaches, and would likely incorporate interactions with constructs of worker adjustment, person-environment fit, types of work environments, and gender.