Teacher education based on "reflective practice" consists of observing, analysing and reflecting on teacher performance in order to improve professional practice. This article presents the results of an evaluation of a programme on mathematics teaching carried out using reflective practice. It was targeted at 284 teachers in various stages of the education system, using an approach that combines quantitative (surveys) and qualitative (interviews and reports) methods. While the study shows that the education programme generates high levels of satisfaction, pedagogical appropriateness and learning, its achievements in effectiveness are moderate. Although, in general, what is learned through teacher education is implemented in the classroom, it is done so in an isolated fashion, in other words, individually and without becoming a part of the culture of the school. The results show little evidence of its impact on student learning. The article offers proposals for improving the education programme, while, at the same time, analysing the usefulness of the approach and evaluation tools employed.