The impact of statin therapy on plasma asymmetric dimethylarginine (ADMA) levels has not been conclusively studied. Therefore the aim of the meta-analysis was to assess the effect of statins on circulating ADMA levels. We searched selected databases (up to August 2014) to identify randomized controlled trials (RCTs) that investigate the effect of statins on plasma ADMA concentrations. A weighted meta-regression (WMD) using unrestricted maximum likelihood model was performed to assess the impact of statin dose, duration of statin therapy and baseline ADMA concentrations as potential variables on the WMD between statin and placebo group. In total, 1134 participants in 9 selected RCTs were randomized; 568 were allocated to statin treatment and 566 were controls. There was a significant reduction in plasma ADMA concentrations following statin therapy compared with placebo (WMD: -0.104 μM, 95% confidence interval: -0.131 to -0.077, Z = -7.577, p < 0.0001). Subgroups analysis has shown a significant impact of hydrophilic statins (WMD: -0.207 μM, 95%CI: -0.427 to +0.013, Z = -7.250, p < .0001) and a non-significant effect of hydrophobic statins (WMD: -0.101 μM, 95%CI: -0.128 to -0.074, Z = -1.845, p = 0.065). In conclusion, this meta-analysis of available RCTs showed a significant reduction in plasma ADMA concentrations following therapy with hydrophilic statins.