BackgroundReal‐world evidence on immune‐related adverse events (irAEs) are relatively insufficient. Herein patterns and outcomes of irAEs after administration of anti‐programmed cell death 1 (PD‐1) and its legend 1 (PD‐L1) antibodies were investigated.MethodsPatients treated with anti‐PD‐1/PD‐L1 drugs from January 2018 to September 2021 at Huadong Hospital, Fudan University were included. Common Terminology Criteria for Adverse Events (CTCAE) was used for irAEs evaluation. The primary endpoints were the clinical description of irAEs.ResultsTwo hundred and forty‐one solid tumor patients were included, with lung cancer as the most common tumor type (56%). 187 (77.6%) patients presented any kind of irAEs. The median time to any irAE onset was 28 (95% CI 24–32) days. Skin toxicities are the most common irAEs (46.1%) and the irAEs (36.5%) occurred earliest after immune‐checkpoint inhibitors. The most frequently occurred all‐grade irAEs were rash (23.7%), myelosuppression (20.7%), and hepatic injury (19.5%). 23 (9.5%) patients died of severe irAEs, which consists of 10 patients with pneumonitis, four colitis, four myocarditis, and one each for gastritis, pulmonary embolism, myelosuppression, hypophysitis, and encephalitis. Patients with any irAE onset had significantly longer progression‐free survival (PFS) (p = 0.013) and overall survival (OS) (p = 0.007), respectively, than patients without irAEs. In addition, patients with skin toxicities (p = 0.012) or blood toxicities (p = 0.015) had achieved a longer PFS, than those without corresponding toxitities, respectively.ConclusionMost irAEs are mild and manageable, while some irAEs can present at later time or can be life‐threatening, especially pneumonitis as we observed. Patients with any irAE onset may achieve a better prognosis than those without irAEs, and presentation of skin or blood toxicities will indicate a better PFS.