Thrombotic thrombocytopaenic purpura (TTP) is characterised by platelet aggregation in the capillaries, thrombocytopaenia and microangiopathic haemolytic anaemia that result in organ ischaemia, mainly of the CNS and kidneys. Since the institution of plasma exchange therapy no further treatments have been proved to improve the survival and the relapse rate of TTP patients. In this retrospective study, we evaluated the efficacy of normal human immunoglobulin treatment in 44 patients suffering from TTP. Patients were divided into two groups that either did not receive (group A: 15 patients) or received (group B: 29 patients) 400 mg/kg of human normal immunoglobulin intravenously (ivIgG) for 5 days. All patients received treatment with corticosteroids, anti-platelet agents and plasma exchange. The results clearly showed that there was no statistically significant difference between the two groups in either remission rate or time to relapse following remission. In conclusion, this study did not prove any beneficial effect of ivIgG in the treatment of TTP patients.