Background Life-long red blood transfusion remains the main treatment for severe thalassaemia. The development of haemolytic alloantibodies and erythrocyte autoantibodies complicated transfusion therapy in thalassaemia patients.

Methods and Materials The frequency causes and prevention of this phenomenon among 80 transfused thalassaemia patients were evaluated in Ali Asghar Children’s Hospital during 1998–2004 (cross-sectional).

Resut In our study the mean age at the initiation of transfusion was 1.7 years (SD 1.94) and mean interval of transfusion 33.73 day (SD 20.74). Autoimmunisation in 15 patients was positive, eight patients had haemolytic reaction in transfusion.

Conclusion Our data show that alloimmunisation to minor erythrocyte antigens and erythrocyte autoimmunisation of variable clinical significance are frequent findings in transfused thalassaemia patients. However, data suggest that the prevalence of immunisation in our patients is less than in other Asian countries.