The purpose of this case study is to investigate the professional mathematics teacher identity (PMTI) of prospective teachers in terms of how the individual perceives her professional identity and how that identity is actualised in the classroom. The participants were required to discuss and describe their own PMTI in terms of three aspects: mathematics specialisation, teaching-and learning specialisation, and caring. Subsequently, they were observed in the classroom, where the actualisation of their PMTI was considered in terms of the same three. These prospective teachers demonstrate that while they may certainly be teaching who they are, this is not necessarily who they think they are. They may believe that they are Mathematics Specialists, Teaching-and-learning Specialists, and Carers, but when they are observed at work in the classroom these specialisations are not necessarily, or at least not consistently evident.