Sciatic nerve block (SNB) is commonly performed in combination with femoral nerve block (FNB) for postoperative analgesia following total knee arthroplasty (TKA). This systematic review examines the effects of adding SNB to FNB for TKA compared with FNB alone on acute pain and related outcomes. Four intermediate-quality randomized and 3 observational trials, including a total of 391 patients, were identified. Three of 4 trials investigating the addition of single-shot SNB and 2 of 3 trials investigating continuous SNB reported improved early analgesia at rest and reduced early opioid consumption. Only 2 trials specifically assessed posterior knee pain. We were unable to uncover any clinically important analgesic advantages for SNB beyond 24 hours postoperatively. At present, there is inconclusive evidence in the literature to define the effect of adding SNB to FNB on acute pain and related outcomes compared with FNB alone for TKA.