The hierarchical model of achievement motivation assumes that individual characteristics predict achievement goals, which further predict achievement outcomes. One of the individual characteristics that may be particularly important in subjects that require abstract reasoning, such as mathematics, is need for cognition. Therefore, the aim of the present study was to examine the relationships between the students' need for cognition, achievement goals and different aspects of engagement in mathematics within the hierarchical model of achievement goals. The sample consisted of 543 students from six academic-track secondary schools. Participants completed self-report measures for need for cognition, achievement goals and engagement (both of the latter measures were related to the field of mathematics). Structural equation modelling was used in mediational analyses. Findings are consistent with the hierarchical model of achievement motivation and demonstrated that achievement goals mediated the relationship between the need for cognition and engagement in mathematics.