AIMS: In recognition of the increasing problem of child obesity in London and elsewhere, we were commissioned to build capacity to tackle this major public health concern. This paper describes one of the outputs of this work: to develop and deliver effective brief intervention training on the subject of childhood healthy/unhealthy weight and obesity to be used by anyone who works with children and families, regardless of their job title or level of educational achievement. METHODS: A literature review informed the process. The slim evidence derived was combined with the expertise of an expert working group to develop clear learning objectives for training and then to develop a flexible one-day training programme suitable for delivery to mixed groups of participants, to meet the learning objectives. Evaluation was built into the programme by means of a questionnaire at the end of the training session and by the use of a structured reflective log to be returned by participants once they had put their training into practice. RESULTS: The training programme was delivered free of charge to over 560 people during the course of a Regional Public Health Group-sponsored project. Subsequently it has been delivered to several more audiences working in the NHS, local government and third sectors in London on a not-for-profit basis. CONCLUSIONS: The programme, based on best available evidence and clear evidence of needs, provides a low-cost evaluated intervention that permits people from diverse professional and occupational backgrounds to acquire the knowledge, skills and confidence needed to raise the subject of healthy and unhealthy weight with parents of primary school-aged children and signpost them to appropriate local facilities and services. Although developed in London, the programme may be used anywhere in the UK, with the substitution of local information about prevalence of overweight and obesity and about local services and facilities.