Immune checkpoint inhibitor-related pneumonitis (CIP) is a serious adverse event associated with immune checkpoint inhibitors (ICIs), which are used to treat various malignancies. The incidence of CIP is higher in real-world settings than in clinical trials, with rates ranging from 5% to 19% in lung cancer patients. CIP can lead to severe respiratory symptoms and even death, and its diagnosis and treatment are challenging due to its varied presentation and individual differences in pathogenesis. The mechanisms of CIP involve immune system activation, leading to excessive immune responses that damage lung tissue. Risk factors for CIP include underlying lung disease, smoking history, certain cancer types, drug classes, radiotherapy history, autoimmune diseases, and infections. Predictive biomarkers such as elevated levels of IL-6, IL-10, and neutrophil to lymphocyte ratio (NLR) may help in early detection and management of CIP. Diagnosis of CIP involves imaging studies, pulmonary function tests, and bronchoalveolar lavage fluid analysis. Pathological evaluation of lung tissue can also provide insights into the disease. Effective management of CIP requires early recognition, discontinuation of ICIs, immunosuppressive therapy, and close monitoring. Research is ongoing to develop better predictive biomarkers and treatment strategies to improve outcomes for patients with CIP.Immune checkpoint inhibitor-related pneumonitis (CIP) is a serious adverse event associated with immune checkpoint inhibitors (ICIs), which are used to treat various malignancies. The incidence of CIP is higher in real-world settings than in clinical trials, with rates ranging from 5% to 19% in lung cancer patients. CIP can lead to severe respiratory symptoms and even death, and its diagnosis and treatment are challenging due to its varied presentation and individual differences in pathogenesis. The mechanisms of CIP involve immune system activation, leading to excessive immune responses that damage lung tissue. Risk factors for CIP include underlying lung disease, smoking history, certain cancer types, drug classes, radiotherapy history, autoimmune diseases, and infections. Predictive biomarkers such as elevated levels of IL-6, IL-10, and neutrophil to lymphocyte ratio (NLR) may help in early detection and management of CIP. Diagnosis of CIP involves imaging studies, pulmonary function tests, and bronchoalveolar lavage fluid analysis. Pathological evaluation of lung tissue can also provide insights into the disease. Effective management of CIP requires early recognition, discontinuation of ICIs, immunosuppressive therapy, and close monitoring. Research is ongoing to develop better predictive biomarkers and treatment strategies to improve outcomes for patients with CIP.