IntroductionImproved hand hygiene in contexts with high levels of diarrheal diseases has shown to reduce diarrheal episodes in children under five years. A quasi-experimental multi-country study with matched comparisons was conducted in four rural districts/sub districts in Cambodia, Guatemala, Kenya and Zambia.MethodsCommunity oriented interventions including health promotion for appropriate hand washing was implemented in the intervention sites, through community health workers (CHW) and social accountability mechanisms. Community councils were strengthened/established in all study sites. Using household surveys, information on mother’s handwashing practices and diarrhea incidence of children 2 weeks preceding the study was obtained. Results and ConclusionAccess to safe drinking water was reportedly higher for communities in Guatemala and Zambia (>80%), than those in Cambodia and Kenya (<63%), with significantly higher levels in intervention sites for Guatemala and Kenya. Improved sanitation was low (<10%), for Kenya and Zambia, compared to Cambodia and Guatemala (>40%); intervention sites reporting significantly higher levels, except for Zambia. Hand washing index; hand washing before food preparation, after defecation, attending to a child after defecation, and before feeding children was significantly higher for intervention sites in Cambodia, Guatemala and Kenya (Cambodia, 2.4 vs 2.2, p<0.001, Guatemala, 3.0 vs 2.5, p<0.001, Kenya, 2.6 vs 2.3, p<0.001). Factors significantly associated with lower odds of diarrhea were; mother’s marital status, higher educational status, one or more handwashing practices, wealthier quintiles, older (>24m), and female children. The findings suggest that caretaker handwashing with soap or ash has a protective effect on prevalence of diarrhea in children.