Objectives To overview the systematic reviews/meta-analyses of safety of femoral nerve block (FNB) used as a postoperative analgesic technique in patients undergoing total knee arthroplasty (TKA). Methods We searched databases including The Cochrane Library, PubMed, EMbase, CNKI, WanFang Data, and VIP from inception to July, 2016. Two reviewers independently screened literature, extracted data and used AMSTAR to evaluate the methodological quality of the included studies. The major indexes used to evaluate the safety of FNB were the incidence rates of symptoms including nausea, vomiting, sedation, retention of urine, dizziness, pruritus, hypotension, falls, nenous thromboembolism and deep infection. Results A total of 12 systematic reviews/meta-analyses were included.They assessed the safety of FNB compared with local infiltration analgesia (LIA), periarticular multimodal drug injection (PMDI), epidural analgesia (EA), patient-controlled intravenous analgesia of opioids (PCA) and adductor canal block (ACB), respectively. The methodological quality of included studies were medium, with the scores between 3 to 10. The results of overview indicated that: FNB had lower incidence rates of nausea and vomiting compared with EA and PCA, but had higher than ACB. FNB had lower incidence rates of sedation and retention of urine compared with EA and PCA. FNB had lower incidence rates of dizziness compared with EA and PCA, and lower incidence rate of hypotension compared with EA. Conclusion Current evidence suggests that FNB is safer than EA and PCA. Due to the limited quantity and quality of the included studies, the above conclusions are needed to be verified by more high-quality studies.