OBJECTIVES: Postoperative delirium (POD) is the main neurological complication of surgery. Anesthetic techniques are associated with the development of POD. However, the results of previous studies on the effects of general anesthesia (GA) and regional anesthesia (RA) on POD are contradictory. This updated meta-analysis aimed to compare the incidence of POD among adult patients who have undergone surgery under GA and RA. METHODS: The CENTRAL, MEDLINE OvidSP, and Embase OvidSP databases were searched from inception to August 15, 2022, with no restrictions on language or publication status. Randomized controlled trials (RCTs) assessing the effects of GA versus RA on POD were considered eligible for inclusion. Two investigators independently reviewed the relevant studies, extracted the data, and assessed the risk of bias. Risk ratios (RRs) and 95% confidence intervals (CIs) were calculated using random-effects models. The Grading of Recommendations Assessment, Development, and Evaluation system was used to evaluate the certainty of evidence. RESULTS: Eight RCTs including 4,871 patients were analyzed. We found no difference in the incidence of POD according to the use of GA or RA (RR, 1.10; 95% CI, 0.90–1.34; I2=0%). Further, the risk of POD did not significantly differ between patients treated with GA + RA or GA alone (RR, 0.75; 95% CI, 0.30–1.88; I2=88%). Four studies reported no significant difference between RA and GA in the need for blood transfusion (RR, 0.87; 95% CI, 0.63–1.21; I2=77%). Likewise, in three studies, the effects of RA and GA on all-cause mortality did not significantly differ (RR, 1.35; 95% CI, 0.85-2.16; I2=38%). Finally, RA (standardized mean difference [SMD], 0.00; 95% CI, -0.08–0.08; I2=0%) or RA + GA (SMD, -0.14; 95% CI, -0.51–0.22; I2=69%) did not significantly reduce the length of hospital stay. CONCLUSION: Current RCTs are not sufficient to support the notion that RA could reduce the incidence of POD compared to GA in adult patients. High-quality RCTs are required to verify these results.