Addressing the participation rates in senior secondary mathematics courses in Australian schools remains a critically important issue. In this paper, the authors report on quantitative findings from a study in which all year 11 and year 12 (aged 17-18 years) Australian Tertiary Admissions Ranking (ATAR) students in Western Australia were invited to participate. The aim was to explore the perceptions of these students regarding their enrolment in higher-level mathematics courses. Data from 1633 students were collected using a survey instrument comprised of 12, 5-point, Likert-scale items. Data were analysed by applying two statistical procedures: calculating frequencies of the 12 items in the scale and examining associations with demographic characteristics and individual items through generalised linear modelling. Analyses indicated most students agreed that other courses of study were more attractive, with almost half indicating that they did not like mathematics. In addition, approximately half of the students said that they did not need to enrol in any mathematics course for ATAR or for university entrance. Significant findings were also identified for gender, school type, and school gender. The knowledge gained from this research is valuable in understanding students' reasons for choosing not to enrol in higher-level mathematics courses when they have the option to do so and, more broadly, to address persistently low or declining participation rates in these areas of study.