Spinal cord injuries (SCI) are devastating conditions that often result in permanent neurological damage and loss of function. Conventional treatments offer limited recovery. Stem cell therapy (SCT), particularly through clinical trials, has emerged as a promising strategy to regenerate spinal cord tissue, restore function, and improve quality of life. This review synthesizes the results of major clinical trials from 2000 to 2024, examining various types of stem cells, delivery mechanisms, safety, efficacy, and long-term outcomes. We conclude that while significant progress has been made, consistent clinical benefit remains elusive, and further phase III trials are crucial.