OBJECTIVES:  To investigate the efficacy of probiotics in irritable bowel syndrome (IBS) patients, this meta-analysis was performed. METHODS:  The collected data contained twenty-four clinical trials which fifteen were eligible for meta-analysis and nine were reviewed systematically. All studies were randomized placebo-controlled trials in patients with IBS that investigated the efficacy of probiotics in IBS improvement. Trials were evaluated with Relative Risk (RR) with 95% confidence interval (95% CI). Cochran Q test was used to test heterogeneity with P value 0.05 (P<0.05). Egger and Begg-Mazumdar tests in funnel plot were calculated as publication bias indicators. RESULTS: Probiotics reduced pain severity, symptom severity score and induced adequate general symptom improvement. Distension, bloating, and flatulence were not improved after probiotics treatment when compared to placebo. CONCLUSIONS: Collectively, the results demonstrated the beneficial efficacy of probiotics compared with placebo in IBS patients.