<![CDATA[Background: Diarrhea remains a common health problem among school-aged children and is associated with personal hygiene practices, particularly handwashing. Proper six-step handwashing is an important preventive measure against diarrheal infections. Purpose: To to determine the association between six-step handwashing behaviour and the incidence of diarrhea among fourth- and fifth-grade students. Method: This quantitative analytical study employed a cross-sectional design involving 52 fourth- and fifth-grade students selected through total sampling at Karangrejo Public Elementary School, Yogyakarta, Indonesia, from April 2025 to February 2026. Data were collected using questionnaires on six-step handwashing behavior and diarrhea incidence. Univariate analysis was used to describe the frequency distribution of each variable, while the association between variables was analysed using the Chi-square test. Results: Of the 52 students, 39 (75%) demonstrated good six-step handwashing behavior, while 13 (25%) demonstrated adequate behaviour. Most students (46; 88.5%) reported never having experienced diarrhea, whereas 6 (11.5%) reported having experienced diarrhea. The Chi-square test revealed a statistically significant association between six-step handwashing behaviour and diarrhea incidence (p = 0.012). Conclusion: Six-step handwashing behaviour was significantly associated with diarrhea incidence among elementary school students. Promoting consistent handwashing practices and maintaining proper food and water hygiene are important components of diarrhea prevention. Keywords: Diarrhea; Elementary School Students; Six-Step Handwashing. ]]>
