The aim of this article is to report the results of an empirical study on adolescents' interest, self-efficacy, and vocational interest in technology and design. Following the expectancy-value model, we wanted to know how context-specific interest in technology and perceived self-efficacy in solving technical tasks are developed at lower secondary-school level and how they predict vocational interest in technology. These personal-trait variables were operationalized in an online survey conducted among 480 students (seventh and eighth grade) in Northwestern Switzerland. Quantitative analyses showed that interest, self-efficacy, and vocational interest vary with respect to theoretical, practical, and creative activities. Moreover, there were marked gender differences in interest and self-efficacy, especially regarding "Using and repairing technical tools" and "Understanding technological processes." No gender differences could be found in "Designing in the context of sustainability," however. Interest, self-efficacy, and vocational interest correlate very highly, but self-efficacy can predict vocational interest in technology better than interest. These results are discussed in the context of recent developments (e.g. STEM initiatives) in the field of technology education worldwide and in particular in Switzerland. According to our analyses and the current discussions about more STEM education and technically skilled teaching staff, schools should provide all students with opportunities to deal with technology, thus enabling them to make manifold experiences in theoretical, practical, creative, and critical ways from early childhood until career choice. At present, this does not seem to be sufficiently the case because otherwise girls would probably not have such negative perceptions of their own abilities.