Curriculum reform in Victoria has led to dramatic changes in what is taught in mathematics classes and in how it is assessed. At years 11 and 12, students must choose what subjects they undertake and within these subjects there are varying degrees of choice about what topics will be studied. Some optional topics are "safe" and familiar to teachers, while others are less familiar, and therefore, in the eyes of some, riskier choices. From previous studies we have statistical data about the choices made, both within and between subjects. This study attempts to give voice to the teachers of mathematics, who reflect on their experience after five years of the new system, including a major subject restructuring after three years. In-depth interviews with 40 experienced teachers of mathematics allow them to reflect on the impact of these changes on their own professional practice and that of their colleagues. How has their teaching changed? What professorial development needs have been revealed? How have they handled the choices that they as teachers have to make, and how have they advised students about their choices? Are students over-assessed? How valuable is the learning that takes place with the different modes of assessment? Teachers' views about these important issues give us a glimpse of curriculum change as it happens, and how it affects the lives of individuals.