Background: Common cold and influenza result in an increased number of primary care consultations, significant work/school absences and cause a socio-economic burden. Laypeople’s perceptions and knowledge regarding common cold and influenza prevention is poorly understood and under-researched. Objectives: Our study explores laypeople’s knowledge of prevention of common cold and influenza across three European countries. Furthermore, it investigates if there is any distinction between prevention activities focussing on reasons impacting the attitude towards influenza vaccination as well as investigating cross-country variation. Methods: In total, 85 semi-structured individual interviews were performed across three European countries (Austria n = 31, Belgium n = 30, Croatia n = 24). Qualitative thematic content analysis was performed. Results: Most participants across all three countries made no distinction between the prevention of the common cold and influenza and referenced the same preventative measures for both conditions. They mainly expressed negative attitudes towards influenza vaccination possibly effective but only intended for high-risk groups (bedridden/older people, chronic patients or health workers). There were very few cross-country differences in results. Conclusion: The perception of health risk of contracting influenza and a primary healthcare physicians’ recommendation played an important role in shaping participants’ decisions towards vaccination. Primary healthcare physicians are invited to assess and if necessary adjust inappropriate prevention behaviour through their everyday patient consultations as well as add to the knowledge about influenza severity and influenza vaccination benefits to their patients.