The experiences of patients with diffuse large B-cell lymphoma (DLBCL) treated with chimeric antigen receptor (CAR) T-cell therapy have received little attention. This study aimed to explore the treatment experiences of patients with relapsed or refractory (R/R) B-cell lymphoma during CAR T-cell therapy in China.This descriptive qualitative study was conducted using face-to-face semi-structured interviews with 21 DLBCL patients 0-2 years after CAR-T infusion. Two researchers independently coded the interviews in MAXQDA 2022, and the original data were analyzed by conventional content analysis.Four themes emerged from the transcripts: (1) physiological distress, (2) functional impacts, (3) psychological experience, and (4) support requirement. Participants expressed 29 short-term or long-term symptoms related to their disease and treatment, influencing their daily life and function in a social setting. The participants expressed different negative emotions, polarized expectations about efficacy, and over-reliance on authoritative medical care. Their major concerns and hopes were achieving life goals, being treated with respect, obtaining more information about CAR T-cell therapy, and receiving government financial sponsorship.The patients experienced short-term and long-term symptoms of physical distress. Patients who have experienced failure in CAR T-cell therapy also experience strong negative emotions, such as dependency and guilt. They also require authentic spiritual and financial information that is authentic. Our study may guide the development of standardized and comprehensive nursing care for R/R DLBCL patients undergoing CAR T-cell therapy in China.© 2023. The Author(s).