This article analysed the relationship between the preventive health behaviours of parents and teenagers during the COVID-19 outbreak, taking the Health Beliefs Model (HBM) as a point of reference. We assumed that parents’ behaviours may be a cue to action for adolescents, looking at their preventive health behaviours regarding vaccination against COVID-19, as well as vaccination intention (among unvaccinated people); wearing protective masks where it is compulsory and where it is not obligatory; and maintaining physical distance and disinfecting hands in public places. The collected data were statistically analysed using the Statistica version 13.3 software package for advanced statistical data analysis. Descriptive statistics and correlation for non-parametric data (Spearman’s correlation) were used. Research on a sample of 201 parents and their children revealed that young people engage in preventive behaviour less frequently than parents, but that the likelihood of such behaviour increases if they have a parent’s cue to action. When formulating recommendations, we considered the gender of the surveyed parents, as the questionnaire was mainly completed by women, which may be an indicator of the unequal involvement in addressing the topic of the pandemic and preventive health behaviours, including attitudes towards vaccines.