Diarrhea remains one of the most common infectious diseases among school-aged children and is closely associated with inadequate handwashing practices. Limited knowledge of proper handwashing techniques increases the risk of diarrhea. This study aimed to determine the effect of health education using leaflets on elementary school students' knowledge of handwashing for diarrhea prevention. This study employed a pre-experimental design with a one-group pretest-posttest approach. The study population consisted of 60 third- and fourth-grade students at SD Negeri 1 Abiansemal Dauh Yeh Cani. A total of 38 respondents were selected using simple random sampling. Data were collected using a knowledge questionnaire administered before (pretest) and after (posttest) a 30-minute health education session using leaflets. Data were analyzed using the Wilcoxon Signed Rank Test. Before the intervention, most respondents had poor knowledge (63.2%), while only 18.4% had good knowledge. After the intervention, all respondents (100%) demonstrated good knowledge. Statistical analysis showed a significant improvement in knowledge after the intervention (Asymp. Sig. < 0.001; p < 0.05). Health education using leaflets significantly improved students' knowledge of proper handwashing for diarrhea prevention and can be considered an effective health promotion strategy for elementary school students.

Keywords: Health Education; Leaflet; Handwashing