BackgroundA major cause of diarrheal illness mortality is a failure to seek immediate medical assistance. There is currently no evidence on the reasons that induce caregivers in Berbere Woreda to delayed seeking timely treatment for under-five children with diarrheal illnesses. As a result, the goal of this study was to identify determinants of delay in seeking timely treatment for childhood diarrheal diseases in Berbere Woreda, Bale Zone Oromia Region, South Eastern Ethiopia.MethodsAn unmatched case–control study on 418 child caregivers was conducted from April to May 2021. Cases were 209 children and their caregivers who sought treatment after 24 h of the onset of diarrheal disease symptoms, and controls were 209 children and their mothers/caregivers who sought treatment within 24 h of the onset of diarrheal disease symptoms. Data were collected through interviews and chart reviews using consecutive sampling. A multivariable logistic regression analysis was carried out, with variables with aP-value of 0.05 considered statistically significant. The Hosmer–Lemshow goodness of fit test was used to validate the model, and the variance inflation factor (VIF) was used to test for multi-collinearity.ResultsIn this study, we found that among 418 participants, determinants of delay in seeking timely treatment for childhood diarrheal diseases included mothers with more than two under-five children (AOR = 2.23, 95% CI 1.21–4.11), Divorce (AOR = 2.62, 95% CI 1.087–2.76), age of children < 24 months (AOR = 1.597, 95%,CI (1.008–2.531), and preference for a government health facility for treatment (AOR = 2.56, 95% CI 1.51–4.34). Besides, the odds of mothers aged 25–34 years being two times more likely to delay seeking timely treatment for 5 children with diarrhea were 1.537 (0.560–4.213).ConclusionsAge of children, age of mothers, number of children, preference of health facilities, and marital status were factors influencing the failure to seek treatment within 24 h of recognizing diarrhea in children under the age of five.