Vaccine hesitancy has led to a decline in immunization rates worldwide, posing a threat to herd immunity. Leveraging storytelling's appeal, a pictorial storybook was designed to improve children's vaccine knowledge. This study evaluated the effectiveness of the storybook in improving vaccine knowledge among children aged 8-9 years. The study employed a one-group pre-test-post-test experimental design. The survey questions were divided into two sections: demographic data and vaccine knowledge consisting of eight questions developed from the content of the storybook. A total of seven classes were randomly selected, and each child read the book with the researcher. The researcher facilitated the survey, ensuring that the participants were not guided towards specific answers. The pre- and post-test data was analysed using the Wilcoxon Signed Rank Test in SPSS version 27.0. The mean score improved from 4.43 to 6.25, and the median score increased from 5.00 to 6.00 showing a significant increase in children's knowledge about vaccines after the intervention. The proportion of children with low vaccine knowledge decreased from 49.1% before the intervention to 6.4% after the intervention. Meanwhile, the percentage of children with high vaccine knowledge increased from 6.7% to 41.2%. The Wilcoxon Signed Rank Test confirmed the statistical significance (p < 0.001) of these findings. The pictorial storybook proved to be an effective tool for enhancing children's vaccine knowledge, validating the use of age-appropriate storytelling in health education. This approach can help address vaccine hesitancy, promote early vaccine literacy, and contribute to improved vaccination rates and better public health outcomes.