Background: Maternal knowledge of childhood respiratory infection prevention is relevant to caregiving decisions and the use of health information in primary healthcare settings. Purpose: To compare maternal knowledge scores regarding childhood acute respiratory infection (ARI) prevention before and after video-based health education. Method: A one-group pretest–posttest study was conducted among 40 mothers of children aged 0–59 months recruited through purposive sampling at Community Health Center Kedaton, Bandar Lampung, Indonesia. Knowledge was assessed before and after a digital educational video covering ARI risk factors, symptoms, consequences, and prevention. Data were analysed using descriptive statistics and the Wilcoxon signed-rank test. Results: The mean knowledge score increased from 8.15 ± 1.528 before the intervention to 14.85 ± 0.483 afterward, representing a mean increase of 6.70 points. The difference between paired scores was statistically significant (Z = −5.539, p < 0.001). Conclusion: Maternal knowledge scores were higher after video-based education. The findings may inform supplementary health education for caregivers in primary healthcare settings. However, the study did not measure psychological well-being or caregiving confidence, and its uncontrolled design does not establish causality. Keywords: Caregiving; Childhood Respiratory Infection; Health Education; Health Literacy; Maternal Knowledge.