|| The purpose of this study was to gauge the cognitive developmental levels of first year university science students. The sample consisted of 386 third-level students, with an average age of 18.8 years. The sample was comprised of two first year groups of students, from nine undergraduate science courses. The task used to measure the cognitive developmental levels was one of the Science Reasoning Tasks, developed by the CSMS (Concepts in Secondary Mathematics and Science) team. The profile obtained showed that almost 70 per cent of students were at levels capable of formal operational thought. However, only a very small minority showed capability of late formal operational thought, necessary for meaningful engagement and understanding of many scientific and mathematical concepts. Thirty-two per cent of the university cohort was at concrete levels of cognitive development. A statistically significant gender difference was evident in this study with female students lagging behind male students in this sample, in terms of their cognitive developmental levels. The significance of these results is evident when the students' current cognitive levels are compared with the minimum cognitive level that a student should be at, in order to understand a large amount of scientific and mathematical concepts in second and third level education. More detailed analysis of these results and the implications for third level science education are presented.