The recent British Thoracic Society guidelines recommend that surgical mortality should not be greater than 8% for pneumonectomy and 4% for lobectomy. These cut offs are advanced as guidelines to inform decision making as to whether or not patients with operable lung cancer should be offered surgery. They have been developed from a notion of what acceptable surgical mortality should be. The planning of care for patients with lung cancer involves making choices between different treatments with different outcomes. While it is accepted that the probability of these outcomes is likely to differ among patients, individual patient preferences for them are also likely to vary. Fixed cut offs for surgical mortality mean ignoring this variation. Decision analysis can be used to assist in the complex task of integrating clinical characteristics and varying patient preferences. By considering high risk patients with potentially curable stage Ia non-small cell lung cancer, it is shown that decision analysis has the potential to illuminate decision making and guideline development within the field of cancer care.