Aim: Influenza is a viral disease which should be taken seriously and which leads to great economic losses. Although vaccination is available, the vaccination rate in the German population is only 20 %. One important reason for this is worries about the possible side effects of vaccination. This data survey is intended to investigate whether intensified education on the side effects of vaccination has any effect on the individual assessment of local and systemic reactions. Method: In autumn 2004 2348 volunteers were included in the investigation during an influenza vaccination campaign. 1163 randomly selected employees were informed in detail about possible side effects after influenza vaccination. A second group of 1185 volunteers were given general information on vaccinations before being vaccinated. The two groups were compared with regard to their individual assessment of symptoms occurring after the vaccination and the frequency of visits to the doctor. Results: 10.1 % of all those vaccinated reported side effects in connection with the vaccination. 2.2 % of those who had been given detailed information and 8.3 % of those given the usual information came to the Works Medical Service surgery of their own accord. In those cases where advice was sought because of influenza-like symptoms, an acute infectious disease was the cause significantly more frequently in the group of those given detailed information. The additional time required to provide detailed information on possible side effects of vaccinations was calculated as 20 seconds per vaccinated person, the additional time needed to discuss the symptoms in the surgery was calculated as an average 10 minutes. Conclusions: Detailed information of possible side effects after influenza vaccination is helpful in reducing the number of queries about vaccination reactions. The symptoms occurring after influenza immunisation are assessed better by the volunteers given detailed information. In this way it is possible make better use of the resources for postvaccination medical consultations.