Immunotherapy has become a standard treatment for patients with advanced urothelial carcinoma, and neoadjuvant immunotherapy is currently being extensively explored. This review highlights the initial findings and key clinical therapeutic insights on immune checkpoint inhibitors in the early treatment of muscle-invasive bladder cancer across diverse patient populations. Most available literature consists of clinical investigations involving small sample, single-arm phase II trials, with the primary endpoint being the pathologic complete response rate. Early results of immune checkpoint inhibitors in the neoadjuvant treatment of bladder cancer have demonstrated promising efficacy. However, these findings require confirmation in large phase III clinical trials, with particular emphasis on long-term survival benefits and identifying patients who respond to treatment.