STEM education is present in most recent curriculum reforms around the world. One of the main novelties of this educational movement is the integration of engineering practices into science education. In the Spanish educational context, this implies an important challenge for science teachers. So, this study analyzes whether secondary science teachers are sufficiently prepared for this purpose, as well as to find out their experiences, emotions, and appraisals in this regard. To this end, a questionnaire was designed and administered to 328 secondary science teachers as a representative sample of science teachers in Spain with a confidence level of just over 93%. The reliability of the questionnaire was evidenced by the high degree of internal consistency of the data (α = 0.88). And its validity was determined by means of an exploratory factor analysis. The results reveal that secondary science teachers, in general, have low levels of pedagogical preparation and self-efficacy to integrate engineering practices into science classes, as well as a predominant emotion of insecurity about it. There is also a strong preference among teachers for this to be done in technology subjects. It is concluded that the effective integration of engineering practices into science education is currently a complex challenge that requires ad hoc teacher training plans.
