Worldwide, adolescents are at risk for sexually transmitted infections (STI). In The Netherlands, test rates among young heterosexual people are low and knowledge on the behavioral determinants of testing is scarce. In this study, we investigated STI testing in more detail with two independent samples of 16-25 year old vocational school students (n = 756/n = 1302). The aim of this study was to examine risk perceptions in relation to STI testing among lower educated adolescents in order to inform the development of an intervention promoting STI testing. We compared multiple measures of risk perception, fear of testing, self-efficacy for testing, and risk knowledge between groups of adolescents engaging and not engaging in risk behavior. The ...