The professional preparation of teachers in England and Wales has, since 1992, been increasingly focused in schools as part of a rhetoric for training more 'competent' teachers. However, this may be viewed as part of wider policies in which public sector professionals increasingly find themselves, their expertise and their influence marginalised from wider matters of policy. This paper reports research conducted with an opportunity sample of 90 secondary teacher mentors in which the aim was to explore and examine the perceptions of professionalism which these mentors, key actors in the training process, bring to their training of new entrants to the teaching profession. Our findings suggest a picture which is worrying because it shows a very strong emphasis on only part of the process of training professional teachers. Whilst mentors report that they give heavy emphasis in their training to practical classroom and personal development techniques and issues, what is profoundly worrying is the lack of any significant focus on, or conception of, the wider role of the professional teacher beyond these important technicalities by the mentor to the new entrant. The findings suggest that a cloak of technical rationality shrouds the training of new entrants to teaching and that the profession is either unaware of or unwilling to debate and initiate its new entrants into a rich professional culture.