Background: Regarding the appropriate effect of probiotics in treating acute diarrhea and the high prevalence of non-bacterial acute diarrhea among children in the population. Objectives: The present study evaluates the effect of synbiotic drops in children with acute diarrhea, including the number of hospitalization days, daily excreted diarrhea volume, duration of diarrhea, and reduction in the number of excretions between the case and control groups. Methods: This was a prospective double-blinded and randomized-controlled clinical trial on children aged 6 - 24 months with non-bloody acute diarrhea were included. The reason for hospitalization was diarrhea. In the case group, the patients consume PediLact (Zisttakhmir, Tehran, Iran) drop (Lactobacillus rhamnosus, Lactobacillus reuteri, and bifidobacterium infantis) 109 CFU and fructooligosaccharides. PediLact drop was used with milk or lukewarm food for five days along with other routine hospital cares. The number of hospitalization days, the daily excreted diarrhea, diarrhea duration, and decreasing numbers of excretion in patients were compared. Results: In the current study, 114 children were included. The duration of hospitalization was 3.87 ± 0.9 days in the synbiotic group and 4.26 ± 0.12 days in the placebo group (P-value = 0.001). The time between the onset of diarrhea and recovery was significantly higher in the placebo group than in the synbiotic group (P = 0.032). The number of evacuations was 1.89 ± 0.13 in the synbiotic group and 2.52 ± 0.18 in the placebo group (P = 0.014).