What is known and objective Hyperhaemolytic transfusion reactions are rare life-threatening events predominantly affecting patients with haemoglobinopathies. We report two cases in β-thalassaemia major patients on chronic transfusion therapy and highlight the role of eculizumab in its management. Case summary Patient 1 presented with intravascular haemolysis on day 7 (D7) post-transfusion and responded to treatment with corticosteroids and intravenous immunoglobulin. However, patient 2 presented with severe symptomatic anaemia (D4 post-transfusion) unresponsive to the aforementioned measures. Eculizumab administration led to resolution of the hyperhaemolysis. What is new and conclusion We report the successful management of hyperhaemolysis with eculizumab in a β-thalassemia major patient.