Objective: This review investigates the effectiveness of high-intensity interval training (HIIT) on multiple sclerosis (MS) patients, focusing on cognitive functions, aerobic fitness, exercise capacity, and muscle strength. MS often leads to persistent physical symptoms that hinder daily activities and quality of life. Methods: The review analyzed studies from various databases, identifying randomized controlled trials comparing HIIT with either healthy individuals or other interventions, up to August 2023. Results: Four studies involving 186 patients were included. Key findings revealed that while HIIT did not significantly improve muscle strength compared to traditional training, it did enhance processing speed in cognitive functions. However, no significant improvements were noted in verbal learning, visuospatial memory, fatigue, or overall aerobic fitness and exercise capacity. A meta-analysis of exercise capacity outcomes indicated moderate heterogeneity among studies, but results were statistically insignificant across VO2 max, workload, and maximum heart rate metrics. Conclusion: It could be concluded that while HIIT may positively influence cognitive processing speed in PwMS, it does not significantly impact other cognitive functions, muscle strength, fatigue, or aerobic fitness. The authors suggest that further randomized controlled trials are necessary to explore the broader effects of HIIT on these outcomes in MS patients, highlighting the need for continued research in this area to better understand the potential benefits of HIIT for improving the quality of life in individuals with MS.