Objective To evaluate the efficacy and safety of vildagliptin vs. placebo for patients with type 2 diabetes.Methods The following databases as The Cochrane Library (Issue 2, 2010), PubMed (1978 to September, 2010), EMbase (1974 to September, 2010), CNKI (1978 to September, 2010), VIP (1989 to September, 2010) and CBM (1978 to September, 2010) were searched to collect the randomized controlled trials (RCTs) of vildagliptin vs. placebo in treating type 2 diabetes. Two reviewers screened the trials according to the inclusion and exclusion criteria, extracted the data, assessed the quality in accordance with the Cochrane Collaboration, and conducted meta-analyses with RevMan 5.0 software. Results A total of 13 studies were included. The results of meta-analyses showed that the vildagliptin given as monotherapy led to greater reduction in HbA1c compared with the placebo (MD= –0.76, 95%CI –0.94 to –0.58, Plt;0.000 01), but it was inferior to the placebo in losing weight (MD=0.68, 95%CI 0.29 to 1.07, P=0.000 6). When the vildagliptin was given as monotherapy, there was no statistical difference in the incidence of overall adverse events (AEs) (OR=1.00, 95%CI 0.83 to 1.21, P=0.98) and hypoglycaemia (OR=1.03, 95%CI 0.65 to 1.65, P=0.89). When the vildagliptin was combined with other oral antihyperglycemic drugs or insulin, it produced greater reduction in level of HbA1c (MD= –0.76, 95%CI –0.94 to –0.58, Plt;0.000 01), and there was no statistically significant difference between vildagliptin and placebo in weight loss (MD=0.40, 95%CI –0.25 to 1.05, P=0.23), AEs (OR=0.95, 95%CI 0.76 to 1.18, P=0.62) and hypoglycaemia (OR=1.11, 95%CI 0.49 to 2.53, P=0.80). Conclusion The vildagliptin treatment for type 2 diabetes is effective and safe. A long-term study in large scale with high quality is required to confirm its long-term outcomes.