There is an urgent need to develop cultural competence among nurses and other care workers if they are to meet the needs of the diverse populations they serve, yet there is limited clarity about what this means, or how it can be measured. To date few attempts have been made to measure the effectiveness of education and training programmes which are designed to promote cultural competence. A research project commissioned by mental health service providers was undertaken to deal with the increasing need for cultural competence in a number of mental healthcare settings. It involved the delivery of a training intervention with an assessment of cultural competence before and after the intervention. The training intervention was negotiated with the participating teams and was based on the model of Papadopoulos et al (1998). The project included the design and development of a tool for assessing cultural competence (CCATool). The paper discusses the challenges faced by the trainers during this intervention and proposes a set of principles for the development of effective cultural competence programmes.