Background and Aims: Diarrhea is the second leading cause of child morbidity and mortality, especially in the developing countries and the primary intervention of its management is oral rehydration therapy (ORT). Adequate Knowledge of ORT was previously defined as one of the determinants of its use. The objective of this work was to identify the predictors of weak knowledge of the Egyptian mothers regarding diarrhea management and ORT use. Method: A convenient sample of 120 mothers presented with their children having acute diarrhea to Suez Canal University hospital were selected. A structured questionnaire about diarrhea and its management were conducted after obtaining the participants’ consent. Results: The mean age of the mothers was 26.7 + 5.4 years and the majority of them79 (65.83%) had 6 to 12 years education. Only 28 (23.3%) of the study group could recognize the inability of eating or drinking as one of the danger signs of diarrhea. Almost all of our study group knew that ORT is an essential treatment modality of diarrhea but only a quarter properly knew its way of preparation and frequency of administration. Mother’s education was the most significant predictor of poor knowledge (β 0.571, p 0.0001) followed by their age (β 0.432, p 0.0001) while other factors like marital state, occupation, child’s age and sex, and number of children were insignificant factors.