Background:This meta-analysis aimed to evaluate the efficiency and safety of intravenous acetaminophen as an adjunct to multimodal analgesia for pain control after total joint arthroplasty (TJA).Methods:PubMed, Embase, Web of science, Medline, and Cochrane library databases were systematically searched. Randomized controlled trials (RCTs) and non-RCTs were included. Fixed/random effect model was used according to the heterogeneity tested by I2 statistic. Meta-analysis was performed using Stata 11.0 software.Results:Four studies including 865 patients met the inclusion criteria. The present meta-analysis indicated that there were significant differences between groups in terms of pain scores at 24 hours (weighted mean difference [WMD] = −0.926, 95% confidence interval [CI]: −1.171 to −0.681, P = .000), 48 hours (WMD = −0.905, 95% CI: −1.198 to −0.612, P = .000), and 72 hours (WMD = −0.279, 95% CI: −0.538 to −0.021, P = .034). Significant differences were found regarding opioid consumption at 24 hours (WMD = −4.043, 95% CI: −5.041 to −3.046, P = .000), 48 hours (WMD = −5.665, 95% CI: −7.383 to −3.947, P = .000), and 72 hours (WMD = −6.338, 95% CI: −7.477 to −5.199, P = .000).Conclusion:Intravenous acetaminophen was efficacious for reducing postoperative pain and opioid consumption than the placebo following total joint arthroplasty. Due to the limited quality of the evidence currently available, more RCTs are needed.