Abstract Background: High-intensity interval training (HIIT) has been proposed as a time-efficient strategy to improve mental health, including anxiety symptoms. However, the evidence regarding its effectiveness across different measurement tools remains inconsistent. Objective: This meta-analysis aimed to evaluate the effects of HIIT on anxiety symptoms and to explore variability across measurement tools and study designs. Methods: A systematic search of COCHRANE, PubMed, Embase, and Web of Science identified eligible studies. Anxiety symptoms were assessed using standardized tools, including DASS-21, STAI, and BAI. Pooled weighted mean differences (WMD) with 95% confidence intervals (CI) were calculated using a random-effects model. Sensitivity analysis and publication bias assessment were performed. Results: Five studies with 464 participants were included. HIIT significantly reduced anxiety symptoms when measured by DASS-21 (WMD: -3.21, 95% CI: -4.48 to -1.95, I² = 0.0%), but no significant effects were observed with STAI (WMD: 0.19, 95% CI: -0.99 to 1.37) or BAI (WMD: 3.70, 95% CI: -0.67 to 8.07). The overall pooled effect size across all tools was -0.76 (95% CI: -3.58 to 2.05, I² = 85.0%), reflecting substantial heterogeneity. Sensitivity analysis indicated robustness of results, with Chang 2024 showing the greatest influence on pooled estimates. Funnel plot analysis suggested potential publication bias. Conclusion: HIIT appears effective in reducing anxiety symptoms, particularly when measured by DASS-21. However, the variability across tools and high heterogeneity highlight the need for further studies to standardize interventions and ensure generalizability.