Chimeric antigen receptor (CAR) T-cell therapy is a relatively new and innovative immunotherapy for haemato-oncological diseases. In the UK, CAR T-cell therapy can be used to treat some patients with relapsed or refractory acute lymphoblastic leukaemia or diffuse large B-cell lymphoma. However, CAR T-cell therapy can have side effects that have implications for patients’ physical and psychosocial well-being and may induce adverse reactions that can cause life-threatening acute toxicities. Nurses may have a significant role throughout the CAR T-cell therapy process, including in supporting patient decision-making, administering infusions, monitoring patients, identifying and managing adverse reactions, and providing follow-up care. This article provides an overview of CAR T-cell therapy and describes some of its potential side effects and adverse reactions. The authors also consider the role of the nurse and the implications for the nursing workforce in terms of meeting the needs of the increasing numbers of patients who may become eligible for this treatment as it is extended to other cancer types.