BackgroundLimited-stage small cell lung cancer (LS-SCLC) is a highly aggressive tumor characterized by a poor prognosis. While concurrent chemoradiotherapy (CCRT) remains the standard treatment, the high rates of recurrence and poor long-term survival highlight the pressing need for novel therapeutic approaches.PurposeIn recent years, the introduction of immunotherapy, particularly immune checkpoint inhibitors (ICIs), has opened new avenues for the treatment of LS-SCLC. This review highlights the clinical advancements of ICIs in CCRT, consolidation therapy, and neoadjuvant therapy, emphasizing their potential to improve progression-free survival (PFS) and overall survival (OS). This review also discusses management of immunotherapy-related side effects.Research DesignThis is a review article that synthesizes recent research findings on immunotherapy for LS-SCLC.Study SampleNot applicable (review of existing literature).Data Collection and/or AnalysisThis review summarizes key studies exploring the application of immunotherapy in limited-stage small cell lung cancer.Additionally, it examines the role of the tumor microenvironment, tumor mutation burden (TMB), and Programmed cell death 1 ligand 1(PD-L1) as biomarkers for predicting the efficacy of immunotherapy.ResultsThis review emphasizes their potential to improve PFS and OS.ConclusionsDespite the significant advancements in research, the use of ICIs in LS-SCLC continues to face challenges, including the identification of optimal treatment regimens, validation of long-term efficacy, and development of personalized predictive biomarkers. Future research should prioritize large-scale, multicenter clinical trials to refine combination therapy strategies, establish customized treatment approaches, and enhance patient outcomes.