Background: General practitioners (GPs) often lack time and resources to invest in health education; audiovisual messages broadcast in the waiting room may be a useful educational tool. This work was designed to assess the effect of a message inviting patients to ask for a tetanus booster vaccination. Methods: A quasi experimental study was conducted in a Belgian medical practice consisting of 6 GPs and 4 waiting rooms (total: 20,000 contacts/year). A tetanus booster vaccination audiovisual message was continuously broadcast for 6 months in 2 randomly selected waiting rooms (intervention group - 3 GPs) while the other 2 waiting rooms remained unequipped (control group - 3 GPs). At the end of the 6-month period, the number of vaccine adult-doses delivered by local pharmacies in response to GPs' prescriptions was recorded. As a reference, the same data were also collected retrospectively for the general practice during the same 6-month period of the previous year. Results: During the 6-month reference period where no audiovisual message was broadcast in the 4 waiting rooms, the number of prescriptions presented for tetanus vaccines was respectively 52 (0.44%) in the intervention group and 33 (0.38%) in the control group (p = 0.50). By contrast, during the 6-month study period, the number of prescriptions differed between the two groups (p <0.0001), rising significantly to 91 (0.79%) in the intervention group (p = 0.0005) while remaining constant in the control group (0.38% vs 0.39%; p = 0.90). Conclusions: Broadcasting an audiovisual health education message in the GPs' waiting room was associated with a significant increase in the number of adult tetanus booster vaccination prescriptions delivered by local pharmacies.