Diarrhea remains a public health problem globally and in Indonesia. Based on 2025 data, diarrhea cases at Puskesmas Nagaswidak were the highest in Seberang Ulu II District. Clean and Healthy Lifestyle Behavior (CHLB), particularly handwashing with soap behavior (HWWS), plays an important role in preventing diarrhea. This study aimed to analyze the association between mothers’ handwashing with…