This study investigated the construct validity of the Mach-IV by testing the differences between the Revised NEO Personality Inventory profiles of Machiavellian- (n = 93) and non-Machiavellian-scoring (n = 92) groups. The two inventories were administered to 94 male and 91 female undergraduates. Results based on multivariate as well as univariate analyses of variance indicated that the Revised NEO Personality Inventory profiles of the Machiavellian and non-Machiavellian groups were significantly different, supporting the construct validity of Mach-IV.