The aim of the study was to investigate the possible impact of comorbidity on survival of patients undergoing composite resection and microvascular reconstruction for oral/oropharyngeal cancer. Patient, tumour and treatment data were recorded. Comorbidity was graded by the Adult Comorbidity Evaluation (ACE-27) test. Survival and statistics were calculated. Comorbidity score ACE-27 grade 2 was present in 47% of patients, for ACE-27 grade 3 this was 13%. The median follow-up was 50 (3-87) months. Thirty-eight patients died, 32 developed a recurrence. Comorbidity score ACE-27 grade 3 turned out to be a clear predictor for overall survival (p<0.05). For ACE-27 grade 3 (n=13) 5-years survival was 29%, for ACE-27 grade 2 (n=87) this was 64%. No multivariate influences on the effects of comorbidity were found. Improved knowledge of the effect of comorbidity on survival may lead to better patient selection and counselling for major surgery and microvascular reconstruction.