Seasonal influenza has become a serious public health problem worldwide and vaccination is recognized as the most effective preventative measure. Healthcare workers can be the vectors of influenza outbreaks. Data suggest that nurses' vaccination remains suboptimal worldwide. To explore the relationship among nurses' knowledge, risk perception and their vaccination behaviours and the reasons for vaccination uptake. A cross-sectional survey. Participants were recruited from the nurses enrolled on continuing professional education courses at a large university in London. A sample of 522 nurses returned completed questionnaires (response rate 77.7%). Most of the respondents were women, worked in hospitals and had direct patient contact. The mean years qualified as a nurse were 11.9 ± 8.75 years. The survey instrument examined nurses' knowledge about influenza and vaccination, risk perception towards influenza and pandemics, vaccination behaviours and reasons for vaccination acceptance or refusal. The survey also collected data regarding gender, age, highest educational qualification, work place, clinical specialty, qualified years as a nurse, and whether they had direct patient contact. The influenza vaccination rate among the respondents was 36% with about 41% never vaccinated. Nurses with a high knowledge level were more likely to get vaccinated compared to those with a low knowledge level (p<0.001). Vaccination rates between the high risk perception and low risk perception groups were different (p=0.019). Sentinel knowledge items were associated with nurses' vaccination status. Several risk perception items including personal vulnerability to influenza or H1N1, mortality risk of H1N1, and the likelihood of transmitting influenza to patients were also predictors of vaccination uptake. Vaccinated nurses were more likely to recommend vaccination to their patients (p<0.001). The most frequent reason for vaccination refusal was concern about the side-effects of the vaccination while self-protection was the most frequent reason for vaccination uptake. This study confirmed a relationship between knowledge, risk perception and vaccination behaviours among nurses. The identified sentinel items of knowledge and risk perception could inform future vaccination campaigns. The clinical specialty of nurses and the importance of accessibility to vaccination as predictors of vaccine uptake require further exploration. Copyright © 2011 Elsevier Ltd. All rights reserved.