AIM: This study aimed to evaluate the effectiveness of probiotics in treating children with acute diarrhoea and dehydration. METHODS: Medline, EMBASE, and the Cochrane Library databases were searched for relevant studies and statistical analysis was performed. RESULTS: A total of 17 randomised controlled trials (RCTs) involving 2861 participants met the inclusion criteria. Compared with placebo, probiotics reduced the duration of diarrhoea (12 RCTs [15, 17], n = 1907, mean difference - 21.33 h, confidence interval (CI) -29.74 to -12.91, high heterogeneity, I(2) = 86%), the duration of hospitalisation when compared with placebo (eight RCTs [19, 20], n = 1606, mean difference - 0.83 days, CI -1.53 to -0.12, high heterogeneity, I(2) = 96%) and reduced risk of diarrhoea on day 4 or more days (six RCTs [19, 20], n = 1093, risk difference - 0.13, 95% CI -0.17- -0.09, no heterogeneity). CONCLUSIONS: Probiotics alongside rehydration therapy appear to be safe and have clear beneficial effects in shortening the duration of diarrhoea in children with acute diarrhoea and dehydration.