Objective: The aims of this study were to examine the symptom severity and interference among patients with lung cancer treated with PD-1 immunotherapy, explore whether those symptoms were clustered together, and identify factors associated with symptom clusters.Methods: A cross-sectional study was conducted. Data were collected by demographic and clinical characteristic questionnaires and the M.D. Anderson Symptom Inventory Lung Cancer Module. Symptom clusters were iden-tified using exploratory factor analysis, and stepwise linear regression was applied to analyze the factors affecting the symptom clusters.Results: A total of 148 patients with lung cancer treated with PD-1 immunotherapy participated in this study. The overall symptom burdens of these patients were mainly at a mild level. The patient symptom clusters identified in this study were a general cluster, a treatment-related cluster, a pulmonary cluster, a gastrointestinal cluster, and a neural cluster. The patients' Karnofsky performance status (KPS) score (fl =-2.758, P < 0.001) and having a history of chemotherapy (fl = 4.384, P = 0.001) were significant predictors of the general cluster. Their KPS scores (fl =-1.202, P < 0.001) and having a history of chemotherapy (fl =-1.957, P = 0.001) were significant predictors of the pulmonary cluster. Their monthly income (fl =-0.316, P = 0.030) and KPS scores (fl =-0.357, P = 0.045) were significant predictors of the gastrointestinal cluster. Having a history of chemotherapy (fl = 1.868, P < 0.001) was the predictor of the neural cluster.Conclusions: The symptom burdens of patients with lung cancer and treated with PD-1 immunotherapy were at a mild level and appeared to be clustered. In addition, because the symptoms that comprise a cluster are interre-lated, the diagnosis and management of each symptom in a cluster should not be performed in isolation, and each symptom in a cluster should be treated either simultaneously or in an orderly manner.