OBJECTIVES: To put into practice and to evaluate an initial dissemination programme for the Strategies for Relatives (START), a clinically and cost-effective manualised intervention for family carers of people with dementia. SETTING: We offered three-hour 'train-the-trainer' sessions through the British Psychological Society and Dementia UK. PARTICIPANTS: Clinical psychologists and admiral nurses across the UK. PRIMARY AND SECONDARY OUTCOME MEASURES: After the training session, attendees completed an evaluation. Attendees were asked how they had implemented START six and twelve months later, and to participate in telephone interviews about their experiences of what helps or hinders implementation oneyear after training. RESULTS: We trained 134 clinical psychologists and 39 admiral nurses through 14 training sessions between October 2014 and September 2015 in nine UK locations and made materials available online. The 40 survey respondents had trained 75 other staff. By this time, 136 carers had received START across eleven service areas. Findings from 13 qualitative interviews indicated that some clinical psychologists had begun to implement START, facilitated by buy-in from colleagues, existing skills in delivering this type of intervention, availability of other staff to deliver the intervention and support from the research team. Admiral nurses did not supervise other staff and were unable to cascade the intervention. Where START has not been used, common barriers included lack of staff to deliver the intervention and family carer support not being a service priority. Participants wanted the training to be longer. CONCLUSIONS: We trained clinical psychologists and admiral nurses to deliver and implement START locally. Results from survey respondents show that it was cascaded further and used in practice in some areas, but we do not know whether START was implemented by non-respondents. Future dissemination requires management buy-in, availability of practitioners and supervisors and consideration of other ways of delivery.