Supraventricular tachycardia (SVT) is one of the most common cardiac arrhythmias, characterized by a sudden increase in heart rate. Initial management often involves vagal maneuvers, including the Valsalva maneuver (VM) and carotid sinus massage (CSM). VM can be categorized into standard VM (sVM) and modified VM (mVM). This study aimed to synthesize the first evidence from published randomized controlled trials (RCTs) comparing the efficacy of VM versus CSM. A comprehensive search across databases, including PubMed, Web of Science, Scopus, Cochrane Library, and Google Scholar, was conducted up to July 29, 2024. The primary endpoint was the success rate of converting SVT to sinus rhythm. The dichotomous outcome was analyzed using a fixed-effect model to calculate the risk ratio (RR) and 95% confidence intervals (CI). The Risk of Bias (RoB) tool, version 2, was employed to assess bias in the included RCTs. In total, three RCTs with 346 cases were analyzed. Concerns were noted regarding potential bias related to the randomization process in all three studies. The meta-analysis of these RCTs (comprising four arms) revealed that VM had a higher success rate than CSM for treating SVT, with an RR of 1.82 (95% CI: 1.29-2.57, p<0.001). Subgroup analysis showed that the rate of conversion to sinus rhythm was significantly higher in the sVM compared to CSM (RR=1.61, 95% CI (1.13-2.29), p=0.01). Additionally, subgroup analysis of one study indicated that mVM was associated with a higher rate of SVT conversion to sinus rhythm compared to CSM (RR=9.28, 95% CI (1.25-69.13), p=0.03). In conclusion, VM demonstrated a higher success rate compared to CSM in treating SVT. Specifically, mVM was more effective than CSM in both terminating SVT and restoring sinus rhythm, though this evidence was based on a single RCT; hence, the related conclusion should be interpreted with caution and requires validation using additional RCTs. Further research in diverse patient populations and clinical settings is necessary to validate these findings and potentially support the broader use of mVM in practice. Additional well-designed, multi-center studies with diverse populations are needed to confirm these observations and provide more comprehensive guidance on SVT management. This is important to enhance the generalizability of results across different demographics and clinical settings. This approach helps ensure that treatment effectiveness is applicable to a broader range of patients, accounting for variations in age, gender, comorbidities, and regional practices.