Chimeric antigen receptor (CAR) T-cell therapy is associated with potentially severe toxicities that create a substantial burden for patients. Patient-reported outcomes (PROs) offer valuable insights into symptoms, functioning, and other complex constructs of interest. In this Review, we aimed to identify symptom and impact concepts important to patients receiving CAR T-cell therapy, construct a conceptual framework for an electronic patient-reported outcome (ePRO) system, and identify timepoints to capture PRO data for CAR T-cell therapies. We searched MEDLINE (OVID) and Web of Science (Clarivate) for articles in English published from Aug 30, 2017, to March 2, 2023. No restrictions on study design were applied. 178 symptoms or constructs were extracted from 44 articles reporting PRO collection in adults with haematological malignancies receiving CAR T-cell therapy. Six health-care professionals and 11 patients and caregiver partners verified construct relevance to clinical management and lived experience, respectively. 109 constructs were sorted according to the four domains of conceptual framework: symptom burden, impact of disease and treatment, tolerability, and health-related quality of life. The identification of concepts beyond symptom burden underscores the importance of PRO measurement for long-term monitoring, to align outcomes with patient concerns. The framework will facilitate PRO measure selection for systematic gathering of PROs from individuals with haematological malignancies receiving CAR T-cell therapies.