Background: Virtual reality exposure and distraction are recent novel technologies for reducing preoperative anxiety symptoms. However, the effectiveness of virtual reality-enhanced interventions in adults is still controversial and has yet to be evaluated in a systematic review. Objectives: The study aimed to (1) evaluate the effectiveness of virtual reality-enhanced interventions on preoperative anxiety symptoms in adults compared to comparators; and (2) identify the factors affecting the effectiveness of interventions. Design: Systematic review, meta-analysis, and meta-regression analysis of randomised controlled trials. Methods: We conducted a three-step systematic search from inception until May 1, 2024, using (1) eleven databases, (2) two clinical registries, and (3) citation and grey literature searches in either English or Chinese. The package meta of R software version 4.3.1 was used to perform the meta-analysis, subgroup analysis, and metaregression analyses. We adopted the restricted maximum likelihood estimator for random-effects metaanalysis and univariate random-effects meta-regression analyses. The Cochrane risk-of-bias tool version 2 and the Grading of Recommendations, Assessment, Development, and Evaluation criteria were used to examine quality assessment and the certainty of evidence. Results: We selected 26 randomised controlled trials with 2357 participants from 12 different countries. Random-effects meta-analyses showed that virtual reality-enhanced interventions had a statistically significant reduction in preoperative anxiety symptoms (t = -5.58, p < 0.001) with a moderate to large effect size (Hedges' g = -0.76, 95 % confidence interval: -1.03 to -0.48) compared to usual care. Statistically significant subgroup differences were found for the nature of the intervention, geographical region, country, and type of surgery. The improvement in preoperative anxiety symptom outcomes was greater when the virtual reality-enhanced interventions were chosen by patients (g = -2.55, 95 % CI: -3.08 to -2.02) when compared to virtual reality exposure interventions with educational content (g = -0.72, 95%CI: -1.07 to -0.38) or virtual reality distraction interventions (g = -0.64, 95 % CI: -1.04 to -0.23). Trials conducted in Asia had a greater effect on preoperative anxiety symptom outcomes (g = -0.98, 95 % CI: -1.33 to -0. 62) in comparison with those conducted in non-Asia (g = -0.23, 95 % CI: -0.54 to 0.07). The random-effects meta-regression identified sample size (beta = -0.008, p = 0.031) as a statistically significant covariate of preoperative anxiety symptoms. The overall certainty of the evidence was very low. Conclusions: Virtual reality-enhanced interventions can be considered supplementary interventions for adults undergoing elective surgery. Future trials on a large scale with follow-up assessments are needed. (c) 2024 Elsevier Ltd. All rights are reserved, including those for text and data mining, AI training, and similar technologies.