During the 1990s, policies for immunizing fit health care workers against influenza varied between National Health Service (NHS) employers and the uptake of influenza vaccine by NHS staff was poor. In light of recent Department of Health recommendations to immunize key health care staff against influenza, we explored the possible reasons for poor uptake and assessed the impact of an intensive promotion campaign on vaccine acceptance. Among 290 doctors and nurses, the main perceived barriers to influenza immunization were difficulty with practical access to vaccine and lack of time to attend. Following intensive promotion and improved local access to influenza vaccine, the uptake among health care workers was approximately doubled. However, the overall proportion of staff immunized was low (5%) and the immunization rate among medical staff was particularly poor (2%). The practical implications for influenza immunization campaigns aimed at health care workers are discussed.