Background: The aim of the study was to evaluate the health-promoting behavior of the preschool children (aged 3–6 y) of Polish health care professionals (HCPs). Methods: The study was conducted by means of quantitative research on a group of 386 individuals, using an Internet-based survey. Results: The ideal cardiovascular health model was determined in the case of 22 children (5.6%). The collected data revealed that, when regarding the recommended level of physical activity, children from HCP families meet the American Heart Association criteria much more often than their peers from other study populations (56.5% vs. 16.6%). In our study, more girls than boys participated in organized activities (60.2% vs. 50.3%, p = 0.05). There was no correlation between achieving adequate levels of physical activity and the BMI (p > 0.1). Overweight children had a more balanced diet than children with a normal body weight (p = 0.009). Conclusions: The obtained results allowed us to make the conclusion that there is a need to implement educational and preventive measures on a large scale, while some health-promoting behaviors, especially those concerning proper nutrition, require major modifications, even in HCP families.