Immune checkpoint inhibitors (ICIs) have revolutionized the treatment of advanced malignancies by targeting tumor cells through the immune system. However, ICIs can also cause immune-related adverse events (irAEs), including immune checkpoint inhibitor-related pneumonitis (CIP), which can be life-threatening. CIP is characterized by widespread respiratory symptoms and parenchymal abnormalities, leading to respiratory failure and even death. Despite the significant clinical benefits of ICIs, the risk of irAEs, particularly CIP, often necessitates discontinuation or switching of treatments, and can result in patient deterioration. The incidence of CIP varies, with real-world studies showing higher rates compared to clinical trials. Factors such as underlying lung disease, smoking history, cancer type, drug classes, history of radiotherapy, autoimmune diseases, and infection are associated with an increased risk of CIP. Early recognition and timely intervention are crucial for managing CIP, which can include discontinuation of ICIs, corticosteroid therapy, and empirical anti-infective therapy. Diagnosis of CIP is challenging due to its nonspecific symptoms and imaging findings. Multidisciplinary approaches, including pulmonary function tests, bronchoalveolar lavage fluid analysis, and pathological examination, are essential for accurate diagnosis. Treatment options for CIP depend on the severity, with grade 1 CIP potentially resuming ICIs, grade 2 requiring temporary discontinuation and corticosteroid therapy, and grade 3-4 necessitating permanent discontinuation and hospitalization. Research efforts are focused on identifying predictive biomarkers and improving diagnostic tools to better manage CIP. Understanding the pathogenesis and developing targeted therapies to prevent or treat CIP is a critical area of ongoing research.Immune checkpoint inhibitors (ICIs) have revolutionized the treatment of advanced malignancies by targeting tumor cells through the immune system. However, ICIs can also cause immune-related adverse events (irAEs), including immune checkpoint inhibitor-related pneumonitis (CIP), which can be life-threatening. CIP is characterized by widespread respiratory symptoms and parenchymal abnormalities, leading to respiratory failure and even death. Despite the significant clinical benefits of ICIs, the risk of irAEs, particularly CIP, often necessitates discontinuation or switching of treatments, and can result in patient deterioration. The incidence of CIP varies, with real-world studies showing higher rates compared to clinical trials. Factors such as underlying lung disease, smoking history, cancer type, drug classes, history of radiotherapy, autoimmune diseases, and infection are associated with an increased risk of CIP. Early recognition and timely intervention are crucial for managing CIP, which can include discontinuation of ICIs, corticosteroid therapy, and empirical anti-infective therapy. Diagnosis of CIP is challenging due to its nonspecific symptoms and imaging findings. Multidisciplinary approaches, including pulmonary function tests, bronchoalveolar lavage fluid analysis, and pathological examination, are essential for accurate diagnosis. Treatment options for CIP depend on the severity, with grade 1 CIP potentially resuming ICIs, grade 2 requiring temporary discontinuation and corticosteroid therapy, and grade 3-4 necessitating permanent discontinuation and hospitalization. Research efforts are focused on identifying predictive biomarkers and improving diagnostic tools to better manage CIP. Understanding the pathogenesis and developing targeted therapies to prevent or treat CIP is a critical area of ongoing research.