<![CDATA[Stunting remains a major nutritional problem among children under five and requires preventive efforts through improving mothers' knowledge. In the target community, health education at the Integrated Health Service Post (Posyandu) was not supported by practical educational media that mothers could review independently. Therefore, the Preventing Stunting Matters pocketbook was introduced as a concise and portable educational medium. This community service program aimed to improve mothers' knowledge regarding stunting prevention. The program was conducted in Trimulyo Village, Sleman District, Special Region of Yogyakarta, Indonesia, involving 30 mothers with children aged 0–59 months. The intervention included pocketbook-based health education, interactive discussions, breastfeeding demonstrations, and pretest–posttest knowledge assessment. Data were analyzed descriptively using the Wilcoxon signed-rank test. The mean knowledge score increased from 94.80 ± 4.83 to 98.80 ± 2.14, with a statistically significant improvement (p < 0.001) and a large effect size (r = 0.70). Although participants had good baseline knowledge, scores increased in 60.0% of participants, while 40.0% maintained their high baseline scores, indicating limited room for further improvement. These findings suggest that the pocketbook has the potential to reinforce maternal knowledge regarding stunting prevention and may serve as a practical educational medium for community-based health promotion.]]>
