Introduction: In the context of a debate on expanding mandatory vaccinations for infants, it is important to explore parents’ sources of information, opinions, practices, and attitudes regarding the vaccination of their child(ren), who will be the first to be affected by this measure. Methods: The 2016 Health Barometer, a random telephone survey, polled 3,938 parents of children aged 1 to 15 about their opinions and vaccination practices regarding two diseases: measles and hepatitis B. Results: the majority of parents report consulting a doctor for information on vaccinations (81.3%); 37.4% conduct research online. Three out of five parents consider hepatitis B and measles to be common diseases; four out of five parents believe their vaccines are effective. Hepatitis B is more often perceived as serious (93.7%) than measles (68.4%); 56.3% of parents believe that the hepatitis B vaccine can cause serious side effects, while 38.4% believe this about the measles vaccine. Parents’ opinions regarding these two vaccines are closely linked to whether their child(ren) have received the vaccinations. In 2016, the proportion of parents reporting that they had vaccinated all their children increased since 2010 for both the MMR vaccine (91.3% vs. 89.4%, p<0.05) and the hepatitis B vaccine (44.8% vs. 29.4%, p<0.001). If the DTP vaccine were no longer mandatory, 86.4% of parents would have their child vaccinated, while 12.8% would “probably or certainly not” do so. A proportionally higher number of people with the lowest incomes would choose not to vaccinate their children (14.3%), as would those who rely solely on the Internet to search for information on vaccination (21.2%). Conclusion: The results confirm the major role of physicians in informing parents about vaccinating their children. Seeking information online is associated with lower vaccination rates, which necessitates strengthening information on the benefits of vaccines and making it accessible, particularly to the most disadvantaged parents; the latter would be less inclined to have their children vaccinated if the DTP vaccine were no longer mandatory. The Vaccination Info Service website was created for this purpose.