Objective To investigate the effects of improved perioperative sleep on pain, analgesic consumption, and postoperative nausea and vomiting (PONV) in patients who were undergoing total knee arthroplasty (TKA) or total hip arthroplasty (THA). Methods Original studies published from 1 January 1970 to 30 September 2020 were queried in three unique databases using a common search term. The searches sought randomized controlled trials (RCT) investigating the effectiveness of sleep quality or quantity interventions for pain control early after TKA or THA. Grey literature was also searched by screening trial registers. There was no limitation on published language and patients. Two reviewers then assessed studies for eligibility. Eligible studies should have primary outcomes including perioperativeWe have comfirmed the edits. visual analogue scale (VAS) pain score and analgesic consumption; and secondary outcomes including side effects, such as PONV. Data extracted from the literature were abstracted into a comma-separated database spreadsheet using Microsoft Excel. A meta-analysis was then performed. Pooled statistics were calculated with weighting by inverse variance assuming a random effect model. I-2 was calculated as a quantifier of heterogeneity and interpreted according to the Cochrane manual. All data analysis was performed using Revman software. Results From a total of 1285 potential records identified in the electronic search, six studies eventually fulfilled the eligibility criteria. The six controlled RCTs consisted of 207 patients in the sleep-improving group and 209 patients in the control group. The severity of rest pain was significantly lower in the sleep-improving group compared with the control group at day 1 and day 3 postoperatively; the severity of active pain was significantly lower in the sleep-improving group compared with the control group at day 3 postoperatively. Data concerning analgesic drugs could not undergo a meta-analysis due to the difference of eligible studies. No significant difference was found in the incidence of PONV between the sleep-improving group and the control group. Conclusion Improved perioperative sleep, regardless of quality or quantity, could significantly reduce the pain level at the early stage after TKA or THA, thus the total amount of analgesic drugs consumed was decreased, without significant increase in the incidence of PONV.