Recent funding decisions on the use of high cost drugs in vulnerable groups have caused problems for the NHS. When working with a finite budget, as commissioners do, a decision to fund one treatment directly reduces the money available for other treatments and services. Clinicians not only have to explain difficult treatment decisions to patients and families, but increasingly find themselves under pressure from the drug industry, pressure groups, and the media to use new treatments. The NHS world class commissioning programme aims to ensure that decisions on funding treatments are robust and based on evidence of cost effectiveness1; however, that information is not always available to clinicians and commissioners. Inconsistencies between the various agencies providing recommendations and developing policies for the NHS are also unhelpful, as our experience with implementing guidelines on the use of palivizumab show.