National policy in the U.K. is to increase the role of General Practitioners (GPs) in treating drug misuse. By working in "shared care" arrangements with specialist services, GPs will become the main providers of treatment, particularly of methadone maintenance. There is little evidence to support the effectiveness of this approach, and GPs' attitudes to treating drug users, their knowledge and prescribing practices give rise to concern. The article concludes that the assumed benefits of treating drug misuse in general practice, which include earlier intervention, greater knowledge of drug users and their families, better treatment of physical health, patient preference for GP treatment and cost-effectiveness, are not supported by research evidence. The article further concludes that, although examples of good practice by a minority of GPs are increasing, a national drug treatment policy should not be based on descriptive models of care. The foundations for an evidence-based policy must be substantiated. References