In this research, we investigate the concerns regarding a national mathematics curricular reform of a cohort of student teachers over the course of their 2-year postgraduate initial teacher education (ITE) programme. The concerns of 41 student teachers from four third-level institutions in Ireland were initially recorded at the commencement of their ITE programme. A qualitative study examining the evolution of these concerns for 12 student teachers was undertaken over three different stages of the 2-year programme. Qualitative responses were generated and analysed according to their stages of concerns. Findings suggest that, at the commencement of their ITE programme, student teachers displayed few informational concerns yet they possessed several incorrect assumptions regarding the intention of the reform. Over time, these concerns evolved towards their capabilities to implement the curriculum in classrooms and consequences of the reform on student learning. At the end of their ITE programme, many expressed concerns about implementing reform practices when they become newly qualified teachers.