The purpose of this article is to create and validate a brief instrument to evaluate attitudes towards persons with disabilities among the adolescent population between 12 and 16 years of age. Disability is currently understood from a contextual perspective (ecological model of disability), as the interaction of a person with her/his surroundings. As part of this interaction, the negative attitudes and expectations towards those with disabilities is still a reason for analysis, as it constitutes one of the main barriers to their inclusion in society. The evaluation of these attitudes in different age groups, using new analytical tools and instruments, is essential for the subsequent design and implementation of intervention measures in order to reverse the said attitudes and improve the collective’s place in society. In this study, there were 1282 participants, students between 12 and 16 years of age. A random selection was carried out, choosing fourteen educational centers in order to analyze the students’ attitudes towards persons with disabilities. The final result was the creation of the CBAD-12A questionnaire, made up of 12 Likert-type items, grouped into three factors: acceptance/rejection, competence/limitation, and equal opportunities. It has been demonstrated that the questionnaire possesses adequate psychometric characteristics, providing research with a new instrument to measure attitudes towards disability. The said questionnaire is useful as a diagnostic and/or predictive measure, allowing us to discover and generate interventions aimed at improving the attitudes of the adolescent population towards those with a disability.