Meta-analysis of the published results from 54 randomised controlled trials of adjuvant chemotherapy in head and neck cancer suggests that chemotherapy might increase absolute survival by 6.5% (95% confidence interval 3.1-9.9%). The odds ratio in favour of chemotherapy is 1.37 (95% confidence interval 1.24-1.5). Single-agent chemotherapy given synchronously with radiotherapy increased survival by 12.1% (95% confidence interval 5-19%). The benefit from neoadjuvant chemotherapy was less: a rate difference of 3.7% (95% confidence interval 0.9-6.5%). The results suggest that the investigation of optimal agents and scheduling for synchronous radiotherapy and chemotherapy might still be important in clinical trials in head and neck cancer.