Hip replacement using hemiarthroplasty (HA) is a common surgical procedure in elderly patients with femoral neck fractures. However, questions remain regarding the choice of unipolar or bipolar HA. A meta-analysis of randomized, controlled trials (RCTs) was performed to determine whether bipolar HA was associated with lower rates of dislocation, reoperation, acetabular erosion, mortality, and general complications, as well as lower Harris Hip Scores, compared with unipolar HA. The authors searched PubMed and the Cochrane Register of Controlled Trials database, and 8 RCTs (including a total of 1100 patients) were selected for meta-analysis. Risk ratios (RRs) and weighted mean differences (WMDs) from each trial were pooled using random-effects or fixed-effects models depending on the heterogeneity of the included studies. There were no differences in dislocation (RR=1.20; 95% confidence interval [CI], 0.47 to 3.07), reoperation (RR=0.64; 95% CI, 0.33 to 1.26), acetabular erosion (RR=2.29; 95% CI, 0.85 to 6.12), mortality (RR=0.85; 95% CI, 0.63 to 1.13), and general complications (RR=1.05; 95% CI, 0.70 to 1.56). The authors found no difference in postoperative Harris Hip Scores between patients undergoing unipolar vs bipolar HA (WMD=-1.32; 95% CI, -3.29 to 0.65; P=.19). Unipolar and bipolar HA achieved similar clinical outcomes in patients with displaced femoral neck fractures.