Background: Acute gastroenteritis is considered as one of the most common causes of under-five morbidity and mortality worldwide. Standard treatment is the use of oral rehydration solution (ORS), intravenous fluid if indicated, and zinc supplement. Recently, the use of probiotics has been introduced as an adjunct to the treatment of acute gastroenteritis. The aim of this study is to determine the clinical efficacy of multi-strain probiotics as adjunct treatment of acute gastroenteritis.