Both in Europe and in North America, teacher education plays a key role in guaranteeing an inclusive school for all and, in particular, is crucial for preparing teachers working with diverse students. However, because of the lack of consistent empirical research in this field, the elements that qualify an effective initial training for teachers working in such contexts are not clear. The prevailing intercultural competence approach is criticized here. Although this approach is, to some extent, very promising for re-envisioning traditional teaching methods, I argue that using a competence model as an a priori framework is less effective in teacher education for handling diversity. Attempting to find a different answer to this question, I will report the results of a critical ethnographic study carried out in Los Angeles focusing on preservice training programs for teachers working in urban schools. Then, I will highlight some practical outcomes I used for designing an in-service training course for teachers and principals in Italy. The analysis showed that teacher education can be effective if knowledge and competence acquisition are combined with emancipatory and empowering processes related to the deepest level of subjectivity, and if political commitment pervades the pedagogical environment in which urban teachers are trained. With the results of this research as my basis, I present the key elements of a two year innovative training course for school principals and teachers set up in Italy, aimed at building what I define as an "intercultural ethos."