A 63-year-old man with relapsed diffuse large B-cell lymphoma received autologous anti-CD19 chimeric antigen receptor (CAR) T-cell therapy. He developed cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome (ICANS), characterized by peripheral facial paralysis and leg tetraparesis. Treatment with tocilizumab and dexamethasone was initiated, but the patient later experienced a second episode of ICANS. Cerebrospinal fluid (CSF) analysis revealed T lymphocytic pleocytosis and macrophage activation syndrome/haemophagocytic lymphohistiocytosis (HLH) features. The patient was discharged after a tapered dexamethasone regimen, with improved general condition but limited mobility. The article highlights the rare but severe complications associated with CAR T-cell therapy, particularly the potential for HLH-like syndrome.A 63-year-old man with relapsed diffuse large B-cell lymphoma received autologous anti-CD19 chimeric antigen receptor (CAR) T-cell therapy. He developed cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome (ICANS), characterized by peripheral facial paralysis and leg tetraparesis. Treatment with tocilizumab and dexamethasone was initiated, but the patient later experienced a second episode of ICANS. Cerebrospinal fluid (CSF) analysis revealed T lymphocytic pleocytosis and macrophage activation syndrome/haemophagocytic lymphohistiocytosis (HLH) features. The patient was discharged after a tapered dexamethasone regimen, with improved general condition but limited mobility. The article highlights the rare but severe complications associated with CAR T-cell therapy, particularly the potential for HLH-like syndrome.