Objective To determine the effectiveness and safety of gelatin tannate (GT) for reducing the duration of the acute diarrhoea and gastroenteritis (ADG) in children. Design Systematic review and meta-analysis. Data sources MEDLINE, Embase, CINAHL, Cochrane Central Register of Controlled Trials, LILACS and grey literature, published from inception to October 2018. No language restrictions. Eligibility criteria for selecting studies Randomised controlled trials in children with ADG, comparing GT with placebo. Results Of 797 titles identified, we included three studies (276 children). We performed a random effects model meta-analysis for the main outcome (diarrhoea duration). We did not find significant differences between GT and placebo for diarrhoea duration (mean difference (MD)=−15.85 hours; 95% CI −42.24 to 14.82, I 2 =92%; three studies), stool frequency at day 2 (MD=0.11 stools/day; 95% CI −0.39 to 0.62: I 2 =26%; two studies), diarrhoea at day 3 (risk ratio [RR]=0.46; 95% CI 0.06 to 3.47: I 2 =73%; two studies), vomiting (RR=1.31; 95% CI 0.95 to 1.80: I 2 =0%; two studies) or adverse events (RR=0.86; 95% CI 0.27 to 2.66: I 2 =0%; two studies). Most common adverse events included abdominal pain and nausea. Conclusion The effect of GT was no different to placebo for mean diarrhoea duration (low certainty on the evidence) and stool frequency at day 2 (high certainty) and for the presence of diarrhoea at day 3 (very low certainty) of vomiting (moderate certainty) and of adverse events (low certainty). PROSPERO registration number CRD42018087902.