While the importance of patient autonomy is widely acknowledged and discussed in 
the bioethics literature, clinicians' autonomy, their ability to make the best 
choices about patients' care free from outside interference, is far less 
debated. This paper takes one form of external influence over clinical decisions 
- the cost of drugs - and applies it to a specific case, that of HER2 positive 
breast cancer and the use of the drug Herceptin in the UK. Drawing on interviews 
with clinicians, researchers and policymakers, I explore the way financial 
decisions about Herceptin shape clinicians' autonomy, and how clinicians as 
individuals and as professional groups respond to these limits and seek to 
provide treatment to the highest number of the most deserving patients they can. 
The point of this paper is not to castigate bioethicists for misguidedly 
focusing on patient autonomy but point out that clinicians' autonomy may be so 
circumscribed by external factors that it may make no sense to speak of their 
actions as stemming from ethical decisions. At the same time, I suggest that 
financial constraints create areas at the margin of clinical practice which are 
deserving of bioethical consideration.