Platinum-induced ototoxic effects are a significant issue because platinum-based chemotherapy is one of the most commonly used therapeutic medications. Sodium thiosulfate (STS) is considered a potential otoprotectant for the prevention of platinum-induced ototoxic effects that functions by binding the platinum-based agent, but its administration raises concerns regarding the substantial attenuation of the antineoplastic outcome associated with platinum. To evaluate the association between concurrent STS and reduced risk of ototoxic effects among patients undergoing platinum-based chemotherapy and to evaluate outcomes, including event-free survival, overall survival, and adverse outcomes. From inception through November 7, 2020, databases, including the Cochrane Library, PubMed, Embase, Web of Science, and Scopus, were searched. Studies enrolling patients with cancer who were undergoing platinum-based chemotherapy that compared ototoxic effects development between patients who received STS and patients who did not and provided adequate information for meta-analysis were regarded as eligible. This study followed the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. The data were extracted by 2 reviewers independently. A random-effects model was used to explore objectives. Relative risks (RRs) for ototoxic effects development and hemopoietic event development comparing the experimental group and the control group were estimated. Secondary outcomes were hazard ratios (HRs) for event-free survival and overall survival. Sensitivity analysis and trial sequential analysis were conducted to further consolidate pooled results. Among 4 eligible studies that were included, there were 3 randomized clinical trials and 1 controlled study. A total of 278 patients were allocated to the experimental group (ie, platinum-based chemotherapy plus STS; 158 patients, including 13 patients using contralatral ears of the control group as samples) or the control group (ie, chemotherapy; 133 patients, including 13 patients using contralateral ears of the experimental group as samples). Overall, patients who received STS had a statistically significantly decreased risk of ototoxic effects during the course of platinum-based chemotherapy (RR, 0.61; 95% CI, 0.49-0.77; P < .001; I2 = 5.0%) without a statistically significant increase in the risk of poor event-free survival (HR, 1.13; 95% CI, 0.70-1.82; P = .61; I2 = 0%) or overall survival (HR, 1.90; 95% CI, 0.90-4.03; P = .09; I2 = 0%). In the trial sequential analysis of event-free survival (z = -0.52) and overall survival (z = -1.68), although the cumulative z curves did not surpass the traditional significance boundary (-1.96 to 1.96 for both) or sequential monitoring boundary (event-free survival: -8.0 to 8.0; overall survival boundary not renderable in the analysis because the information size was too small) of the adjusted CI, they did not reach the required information size. This meta-analysis found that concurrent STS delivery was associated with a decreased risk of platinum-induced ototoxic effects among patients treated with platinum-induced chemotherapy. These findings suggest that concurrent STS for protection against ototoxic effects should be considered for patients indicated for platinum-based chemotherapy.