Handwashing with soap is recognized as a cost-effective intervention to reduce morbidity and mortality associated with enteric and respiratory infections. This study analyzes rural Indonesian households' hygiene behaviors and attitudes to examine how motivations for handwashing, locations of handwashing space in the household, and handwashing moments are associated with handwashing with soap as potential determinants of the behavior. The analysis was conducted using results from a UNICEF cross-sectional study of 1700 households in six districts across three provinces of Indonesia. A composite measure of handwashing with soap was developed that included self-reported handwashing, a handwashing demonstration, and observed handwashing materials and location of facilities in the home. Prevalence ratios were calculated to analyze associations between handwashing with soap and hypothesized determinants of the behavior. Our results showed that determinants that had a significant association with handwashing with soap included: (1) a desire to smell nice; (2) interpersonal influences; (3) the presence of handwashing places within 10 paces of the kitchen and the toilet; and (4) key handwashing moments when hands felt dirty, including after eating and after cleaning child stools. This study concludes that handwashing with soap may be more effectively promoted through the use of non-health messages.