People over the age of 65 are one of the most vulnerable groups when it comes to seasonal influenza in terms of mortality. The flu vaccine is therefore recommended for this population, but vaccination coverage remains well below the target in France. The 2016 Health Barometer, a survey conducted via random sampling, explored the perceptions of 2,418 people aged 65 to 75 regarding seasonal influenza (severity and frequency) and the vaccine (effectiveness, serious side effects), as well as the relationship between these perceptions and their vaccination behavior during the winter of 2015–2016. In 2016, 45.9% of those aged 65–75 reported having received the flu vaccine during the winter of 2015–2016. They considered the flu to be serious (81.3%) and common (92.1%). The vaccine was considered effective by 64.3% of respondents, but nearly half (46.9%) believed it could cause serious side effects. Perceptions of the vaccine’s effectiveness (prevalence ratio, PR=5.28, 95% CI [3.92–7.10]) and, conversely, perceptions of serious adverse effects (PR=0.69 [0.62–0.77]) are strongly linked to flu vaccination uptake. The perceptions of people over 65 regarding the flu vaccine, sometimes based on false beliefs, are linked to their vaccination practices. Even with moderate efficacy, and given its positive risk-benefit balance, flu vaccination helps prevent severe cases of the flu and excess mortality among the elderly. Flu information and communication campaigns must continue to convey this message and combat misconceptions about the vaccine’s safety.