Background: This national qualitative study explores (1) the experiences, observations, and opinions of health care workers (HCWs) about beliefs, socioeconomic, cultural, and environmental characteristics of parents refusing vaccination and (2) regional differences in the identified risk factors; (3) recommended solutions to improve vaccine acceptance in each of 12 regions in Turkey. Methods: In total, we carried out 14 individual semi-structured in-depth interviews and 10 focus group discussions with 163 HCWs from 36 provinces. A thematic analysis was performed to explore HCWs' observations about the parents' decisions to reject vaccination and possible solutions for vaccine advocacy. Results: Within the analyzed data framework, vaccine refusal statements could be defined as vaccine safety, the necessity of vaccines, assumptions of freedom of choice, health workers' vaccine hesitancy, lack of information about national vaccination schedule and components, not trusting the health system, anti-vaccine publications in social media and newspapers, and refugees. Suggestions based on the HCWs suggestions can be summarized as interventions including (1) creating visual cards with scientific data on vaccine content and disease prevention and using them in counseling patients, (2) writing the vaccine components in a way understandable to ordinary people, (3) highlighting the national quality control and production in the vaccine box and labels, (4) conducting interviews with community opinion leaders, (5) training anti-vaccine HCWs with insufficient scientific knowledge and (6) reducing the tax of parents whose children are fully and punctually vaccinated. Conclusions: The solution to vaccine rejection begins with the right approaches to vaccination during pregnancy. Prepared written and visual information notes should present the information as "vaccination acceptance" rather than "vaccination refusal". Further studies on vaccine refusal rates should be carried out in various regions of the world so that region-specific actions are implemented to decrease the anti-vaxxer movement and to prevent an outbreak of infectious diseases.