The modified Simiao decoctions (MSD) have been wildly applied in the treatment of gouty arthritis in China. However, the evidence needs to be evaluated by a systematic review and meta-analysis. After filtering, twenty-four randomised, controlled trials (RCTs) comparing the effects of MSD and anti-inflammation medications and/or urate-lowering therapies in patients with gouty arthritis were included. In comparison with anti-inflammation medications, urate-lowering therapies, or coadministration of anti-inflammation medications and urate-lowering therapies, MSD monotherapy significantly lowered serum uric acid (p < 0.00001, mean difference = -90.62, and 95% CI [-128.38, -52.86]; p < 0.00001, mean difference = -91.43, and 95% CI [-122.38, -60.49]; p = 0.02, mean difference = -40.30, and 95% CI [-74.24, -6.36], resp.). Compared with anti-inflammation medications and/or urate-lowering therapies, MSD monotherapy significantly decreased ESR (p < 0.00001; mean difference = -8.11; 95% CI [-12.53, -3.69]) and CRP (p = 0.03; mean difference = -3.21; 95% CI [-6.07, -0.36]). Additionally, the adverse effects (AEs) of MSD were fewer (p < 0.00001; OR = 0.08; 95% CI [0.05, 0.16]). MSD are effective in the treatment of gouty arthritis through anti-inflammation and lowering urate. However, the efficacy of MSD should be estimated with more RCTs.