Experimental and epidemiological data suggest that vitamin D play a role in pathogenesis and progression of cancer, but prospective data on head and neck cancer (HNC) and oesophagus cancer are limited. The European Prospective Investigation into Cancer and Nutrition (EPIC) study recruited 385,747 participants with blood samples between 1992 and 2000. This analysis includes 497 case-control pairs of the head and neck and oesophagus, as well as 443 additional controls. Circulating 25(OH)D3 were measured in pre-diagnostic samples and evaluated in relation to HNC and oesophagus cancer risk and post-diagnosis all-cause mortality. After controlling for risk factors, a doubling of 25(OH)D3 was associated with 30% lower odds of HNC (OR 0.70, 95% confidence interval [95% CI] 0.56-0.88, Ptrend = 0.001). Subsequent analyses by anatomical sub-site indicated clear inverse associations with risk of larynx and hypopharynx cancer combined (OR 0.55, 95CI% 0.39-0.78) and oral cavity cancer (OR 0.60, 95CI% 0.42-0.87). Low 25(OH)D3 concentrations were also associated with higher risk of death from any cause among HNC cases. No clear association was seen with risk or survival for oesophageal cancer. Study participants with elevated circulating concentrations of 25(OH)D3 had decreased risk of HNC, as well as improved survival following diagnosis.