Having children compels parents to examine their vaccine beliefs, particularly if they are vaccine-hesitant or refuse all vaccines. Presently, little is known about the specific ways in which having children influences the vaccine beliefs of parents. This research examined how having children changed the attitudes of Australian vaccine-hesitant and vaccine-refusing parents towards childhood vaccination. We asked 904 Australian parents who believed that having children changed their attitudes to vaccination to describe these changes. Parents' responses were inductively, iteratively coded and thematically analysed. Themes were compared between parents who believed all vaccines should be refused, parents with varying degrees of vaccine hesitancy, and parents who were fully vaccine-accepting. Low numbers of responses from fully vaccine-accepting parents meant that this paper focused on mostly vaccine-hesitant and vaccine-refusing vaccine parents. Five themes were identified. Having children prompted all parents to learn about vaccine choices. Hesitant and refusing parents' interpreted vaccine choices through a lens of distrust of pharmaceutical companies and regulatory bodies overseeing vaccine safety. The distrust fuelled parents' fears about vaccination risks, such as side effects. Parents became concerned about the scheduled timing of vaccinations, particularly of the Hepatitis B vaccine. Parents among the three groups that believed some or all vaccines should be refused reported that a vaccine permanently injured their child. This research contributes to understanding how having children affects the vaccine attitudes among vaccine-hesitant and vaccine-refusing parents. Greater support for parents with negative vaccination experiences may prevent hesitant attitudes. The vaccination schedule needs to be communicated to parents better.