In 3 studies (respective Ns = 289, 394, and 1,678), males and females were assessed on Big Five traits, masculine instrumentality (M), feminine expressiveness (F), gender diagnosticity (GD), and RIASEC (Realistic, Investigative, Artistic, Social, Enterprising, Conventional) vocational interest scales. Factor analyses of RIASEC scores consistently showed evidence for D. J. Prediger's (1982) People–Things and Ideas–Data dimensions, and participants' factor scores on these dimensions were computed. In all studies Big Five Openness was related to Ideas–Data but not to People–Things. Gender was strongly related to People–Things but not to Ideas–Data. Within each sex, GD correlated strongly with People–Things but not with Ideas–Data. M, F, and Big Five measures other than Openness tended not to correlate strongly with RIASEC scales or dimensions. The results suggest that gender and gender-related individual differences within the sexes are strongly linked to the People–Things dimension of vocational interests.