BACKGROUND Ulcerative colitis (UC) is an acute and inflammatory disease of the large bowel of unknown aetiology. The use of probiotics for this disease remains controversial. The objective of this systematic review was to identify studies based on randomised controlled trials comparing the effect of probiotics to the effect of anti-inflammatory drugs or placebo in the remission of UC. METHODS We conducted a systematic review of clinical trials comparing the effect of probiotics to the effect of anti-inflammatory treatment or placebo in the remission of UC. PubMed, scienceDirect, Cochrane, Google scholar, metaRegister of Controlled Trials and National Institutes of Health were searched. RESULTS Nine studies met the inclusion criteria. These studies present a significant heterogeneity concerning their methodology and their results. The improvement in UC remission and the frequency of adverse effects do not differ significantly between probiotic and control groups. CONCLUSIONS There are a limited number of randomised trials published in the field of probiotics used for the remission of UC, and they present many methodological differences. The existing studies suggest a similar safety and efficacy of probiotics in comparison with anti-inflammatory drugs.