Since people's attitude toward lesbians, gay men and bisexual people (LGB) affects young LGB people's mental health and subsequently their quality of life, it is important to establish people's attitudes toward LGB people. The current study examined attitudes toward lesbian, gay and bisexual people among Dutch students and the psychometrical characteristics of adapted instruments measuring attitudes toward sexual diversity. The students in the sample (N = 1.633) were recruited from secondary schools. The participants completed questionnaires with scales measuring attitudes toward LGB people. The results indicate that participants hold positive attitudes overall, but there are differences with regard to gender and educational level. In addition, the used instruments prove to be psychometrically sound for measuring LGB attitudes and this work contributes to the empirical debate about whether adolescents' attitudes toward lesbians, gay men and bisexual people underly domains of a general attitude toward LGB people. Our results indicate that students do not seem to distinguish among sexually diverse subgroups much, possibly a sign of increased awareness and knowledge of LGB groups. The use of one general measure of attitudes of sexually diverse people may be considered in future research.