The purpose of this paper was to design and validate a questionnaire of perception of elementary education teachers about the inclusion of the key competences in the curriculum. Initially, thirteen dimensions and 65 items of the main elements of learning competences were defined. In the content validity, experts (n = 35) assessed positively construct, dimensions and items. In the comprehension validity, teachers (n = 45) confirmed the adequacy of the criteria. In the construct validity (n = 255 teachers), the confirmatory factor analysis corroborated the good fit of the model: chi(2)/g.l.: 2.03, TLI: .94, CFI: .91, RMSEA: .06, y SRMR: .04. The final version of the Questionnaire of Perception of Elementary Education Teachers on the Inclusion of Key Competences (#ICOMpri3)