Over recent years increasing attention has been given to professional development for aspiring heads in the UK and elsewhere. In Scotland, the Scottish Qualification for Headship (SQH) was devised as a means of preparing for headship. This paper draws from the national evaluation of the SQH in order to assess the extent to which this programme appears to be achieving the development of the kinds of leadership qualities which have been identified as significant in recent research. However, the paper does not focus simply on the development of the qualities of the individual candidate but looks at the impact of the SQH in the wider professional setting, particularly in the schools where candidates are working. It appears that the programme has been effective in many instances in engaging with the dynamic emotional and professional dimensions of teacher development and in contributing to school improvement.