Despite concerns about declining interest and enrolments in mathematics, little research has examined change in a broad range of constructs reflecting mathematics motivation and engagement. The current study used an 11-factor model of motivation and engagement to evaluate levels of maths motivation compared to general academic motivation and to assess group-level and individual-level changes in maths motivation during secondary school. In a multicohort-multioccasion design, Australian students completed an adaptation of the Motivation and Engagement Scale in two consecutive school years. Ratings in mathematics were lower than general academic motivation on several scales but particularly on the planning and task management scales and for the year seven cohort. Mean ratings of valuing and task management decreased over the two years, while stability of mathematics motivation was moderate. Girls reported stronger anxiety, uncertain control and failure avoidance than boys, despite also reporting greater mastery focus. The findings demonstrate that a multidimensional model facilitates a differentiated analysis of possible reasons for a waning interest in mathematics. (Contains 5 tables.)