Complex surgery with curative intent as part of the care of patients with head and neck cancer, who also have serious coexisting conditions is sometimes viewed critically as being unduly, optimistic. We have used American Society of Anesthesiologists’ (ASA) grading by a single anaesthetist prospectively as a baseline to investigate a possible link between coexisiting conditions and disease-free survival in 114 patients with head and neck cancer patients treated by the same anaesthetist and surgical team, and found that the ASA grade is not a reliable predictor of disease-free survival. There was no significant association between ASA grade and overall mortality, but there was a significant association between ASA grade and mortality associated with metastatic disease. However, the test for trend was not significant, which suggested that deaths from metastatic disease did not increase in line with ASA grading. All patients in ASA grades II and III were alive 2 years after their initial operation and the risk of mortality after 2 years may increase by up to 10%.