Background: The prevalence of obesity in the UK has reached epidemic proportions and is continuing to increase. Obesity is one of the most important avoidable risk factors in men and women for diseases such as coronary heart disease, stroke, non-insulin dependent diabetes mellitus and hypertension. Modest weight loss of 5–10 kg or 5–10% of initial body weight maintained for the long term reduces the health risks associated with obesity. Reducing levels of obesity in the population has proved to be particularly challenging. The Department of Health (DH) wished to help practitioners in the field by allocating funding to identify and encourage good practice in weight management. Aims: The project had two aims: firstly, to promote the skills of evaluation at local level and to disseminate the results of evaluation more widely. DH’s Advisory Group agreed that the project would identify existing projects on weight management in the regions and a directory of services would be compiled. The second aim was to contribute up to £5000 to a number of projects to help them to evaluate their work, and disseminate the results. Methods: Questionnaires were sent out via a number of local networks in each region to identify suitable projects and services. The responses were compiled into a Directory which is available as a database at each Regional Office. One hundred and sixteen of the services identified indicated that some evaluation had been carried out, and were either available in report form or currently being written up. Those whose services were not evaluated were invited to submit a proposal. Evaluations of 13 weight management services involving different types of intervention and various practitioners were commissioned in September 1997. Expert advice was made available at the start and throughout the project. The evaluations were completed by the end of March 1998. Results: The evaluations suggest that: (1) successful sustained clinically significant weight reduction in obese patients is rare. Most of the interventions evaluated showed initial weight loss in some patients but this was rarely maintained at follow-up; (2) successful weight loss is achieved through multicomponent programmes that aim to bring about lifestyle (behavioural) changes to reduce energy intake and increase energy output in ways that are practical and easy to sustain. This is achieved through multidisciplinary teams of health care workers and physical activity instructors; (3) regular contact and follow-up between patient and practitioners are important for successful weight loss and weight maintenance. More work is needed to develop strategies that may improve long-term weight maintenance. Conclusions: Evaluation of existing and new weight management services and dissemination of the results will identify the most effective methods for the treatment of obesity which can be employed by all health care teams. Evaluations need to be considered at the planning stage for the services so that appropriate data and research methods are included. Health Authorities should consider how best to provide advice and help to practitioners whose research experience is limited.