ObjectiveTo improve clinicians' understanding of severe cytokine release syndrome (CRS) through reporting the clinical manifestation, diagnosis, treatment, and prognosis of CRS after chimeric antigen receptor T (CAR-T) cell therapy in a patient with solid tumor. Methods A patient with ovarian cancer who suffered severe CRS after CAR-T cell therapy in the Department of Critical Care Medicine, the First Affiliated Hospital of Nanjing Medical University was reviewed. Relevant studies were searched for literature review. Results The patient, a 55-year-old woman, was diagnosed with ovarian cancer in early 2016 and continued to progress despite multiple lines of treatment, so she received CAR-T cell therapy on September 16, 2022. The patient developed a fever 2 days after infusion, and developed dyspnea and shortness of breath with oxygen desaturation 2 days later. Her condition kept deteriorating with respiratory distress and severe hypoxia 6 days after infusion, and the level of interleukin-6 and interferon-gamma continued to be elevated. Chest CT showed pleural effusion and massive exudation of both lungs. Considered to have acute respiratory distress syndrome (ARDS) due to severe CRS, she was transferred to the intensive care unit (ICU). The patient was treated with tocilizumab, high-dose intravenous glucocorticoid pulses, mechanical ventilation, and sivelestat sodium for ARDS. Her symptoms were gradually relieved, and the results of laboratory tests were gradually stabilized. The patient was extubated 6 days after ICU admission and discharged from ICU a week later. Six patients were screened out with ARDS or acute respiratory failure caused by CRS after CAR-T cell therapy, whose treatments were mainly anticytokine agents combined with high-flow oxygen therapy or invasive mechanical ventilation. One of them died. ConclusionsClinicians should be alert to severe CRS during the administration of CAR-T cell. Rapid interruption of the inflammation development is the key to all treatments. If respiratory and/or circulatory dysfunction occurs, patients should be transferred to ICU in time for organ support therapy.