The present article describes the development and validation of the Informational and Normative Conformity Scale (SKI-N), a brief self-report tool capturing adolescents' general propensity to adopt a conformist attitude, and the underlying motives for doing so. The presentation includes a description of scale construction and an assessment of the psychometric properties. In two independent samples of adolescents (total N = 1,953), the SKI-N factorial structure was investigated, and the reliability and dimensionality, the multi-group measurement invariance, and the construct validity were each verified. The findings showed that the scale structure is bi-factorial, and the tool is reliable, valid, and invariant across gender. Therefore, the SKI-N can be applied in research and/or in psychological and educational practice to provide important information in a broader assessment of students' psychosocial functioning in the school environment. Moreover, compared to currently available measures, it fills a gap in the tools for measuring conformity in the adolescent population.