An research was carried out to determine the vocational preferences of 1159 students (764 males and 392 females) in the last two years of high school in the province of Arequipa (Peru) in the light of sociodemographic and family variables. The emphasis was directed towards STEM (Science, Technology, Engineering and Mathematics) degrees and with the intention of knowing their specific distribution by area of knowledge. The most relevant results show the existence of a predilection for engineering degrees, and where the natural sciences did not merit significant preferences. In this panorama, it was found that men showed interest in engineering and in comparison with women. These findings are discussed from an epistemological perspective based on critical realism, which proposes -among other aspects- the transcendental relevance of natural sciences and mathematics for the sustained, pertinent and harmonious development of engineering.