Despite Department of Health recommendations that healthcare workers (HCWs) receive influenza vaccination, uptake is low. Influenza vaccination has been promoted to reduce nosocomial transmission and staff absenteeism during the winter period. Our study aimed to investigate factors associated with uptake, and non-uptake, of influenza vaccination. In March 2001 we undertook a questionnaire-based cross-sectional survey of 604 hospital HCWs in Leicester and 11 occupational health nurses. Following multivariate analysis, uptake was associated with previous influenza vaccination (OR: Odds ratio 1000, 95% CI 20-3,333), age > 45 years (OR 4.45, 95% CI 1.66-11.9), and belief that influenza is a serious illness (OR 3.8, 95% CI 1.3-10.6). HCWs receive vaccination predominantly as a benefit for themselves. Campaigns should improve accessibility, target younger staff and stress the consequences of influenza infection. Simply raising awareness may not translate into increased uptake. Absenteeism was attributed to vaccine-related adverse effects by 11/83 (13%) vaccinees, resulting in 0.46 workdays lost per dose administered.