BackgroundWater, sanitation, and hygiene (WASH) interventions, which are specifically targeted towards young children—known as “BabyWASH”—reduce exposure to environmental contamination and prevent microbial burden in their play and feeding environments. The purpose of this endline study was to evaluate the effectiveness and potential sustainability of a multimedia educational intervention in influencing key BabyWASH and diarrhea prevention practices in four hard-to-reach woredas (i.e. administrative districts) of the Afar and Somali regions of Ethiopia.MethodsA mixed-method, comparative cross-sectional study was conducted, which included 457 household surveys, 16 key informant interviews, and 8 focus group discussions. The multimedia educational intervention comprised: broadcasting radio talk shows and radio spot messages, capacity-building training for community health workers and community leaders, community mobilization campaigns, and the distribution of promotional print media materials. Propensity score matching analysis was used to estimate the effect of the multimedia educational intervention on key BabyWASH and diarrhea prevention attitudes and practices, which was then triangulated with qualitative findings.ResultsThe multimedia intervention had a significant positive impact on good BabyWASH and diarrhea prevention practices, including appropriate practices of child feces disposal (t-test = 5.17; p < 0.001), handwashing with soap or ash (t-test = 8.85; p < 0.001), maintaining separate playgrounds for young children (t-test = 2.83; p < 0.001), washing of child’s body, hands, and faces (t-test = 15.78; p < 0.001), and food hygiene practices (t-test = 2.74; p < 0.05). The findings of the qualitative assessment also revealed that the multimedia intervention packages and the approaches used were successful in influencing key BabyWASH and diarrhea prevention behaviors in the intervention implementation woredas. In addition, providing capacity building training to local actors and community leaders and recording radio talk shows and sharing them with community members were recognized as effective intervention implementation strategies.ConclusionThe endline evaluation found that the multimedia educational intervention improved awareness, perception, and practice of BabyWASH and diarrhea prevention behaviors in intervention woredas compared to control woredas. Sanitation and hygiene promotion interventions in pastoralist settings can be effective when using locally and contextually appropriate intervention strategies. However, considerations for integrating both behavioral and structural components in WASH interventions is essential.