Introduction. Preventive vaccinations are the most effective and the cheapest method of fi ghting and preventing infectious diseases. They preclude the development of complications and limit the spread of infections. Over the years, there has been a signifi cant development and growth in disease prevention due to the implementation of preventive vaccination plans, both recommended and compulsory. Aim. The aim of the study was to examine parents' opinions on the refusal of preventive childhood vaccines. Material and methods. The study covered 100 patients of the obstetric ward at the Independent Public Complex of Healthcare Facilities 'Zdroje' in Szczecin. The diagnostic survey method in the form of authors' self-designed questionnaire was used in the study. The results were prepared using the R program, version 3.4.3. R Core Team (2017). Results. Among 100 respondents, only 12.0% think that preventive vaccinations of children are unnecessary. The study shows that 32.0% of parents are not familiar with the obligatory vaccination calendar. Most respondents do not carry out any additional recommended vaccinations on their children (61.0%). More than half of the respondents (60.0%) are afraid of preventive vaccinations. A slight majority of the respondents buy vaccines instead of using the reimbursed vaccinations (52.0%). The main sources of parents' knowledge on the issue of preventive vaccinations are doctors, nurses, midwives and the Internet (81.0% each). Most respondents (53.0%) think that there should be penalties for guardians who do not vaccinate their children. Conclusions. 1) The level of parents' knowledge on infectious diseases and the rationale of vaccinating children is deteriorating due to the infl uence of unreliable sources of information, 2) The Internet is an important source of knowledge on the issue of vaccinations, 3) It is advisable to intensify and concentrate the efforts of healthcare professionals in having reliable and accurate knowledge on preventive vaccinations that they convey to parents.