To evaluate left and right ventricular myocardial performance using pulsed-tissue Doppler imaging (TDI) and its relation to BNP levels in patients with beta-thalassaemia major (beta-TM). We enrolled 36 thalassaemic patients (21 male, 15 female; mean age: 14.2 +/- 4.1 years) with normal left ventricular systolic and diastolic functions with conventional echocardiography and 30 healthy control subjects (18 male, 12 female, and 12.5 +/- 4.2 years). Myocardial performance indexes (MPI) of left ventricular (LV) lateral wall, interventricular septum (IVS) and right ventricular (RV) lateral wall were calculated with TDI. Plasma BNP levels were measured in all patients. MPIs and other echocardiographic parameters of patients with beta-TM were compared with control group. All the patients' plasma BNP levels were within normal limits. There were no differences between conventional echocardiographic parameters of patients and control group. MPI of LV, IVS, and RV of patients were significantly higher than control group (P = 0.01, and P < 0.01, and P < 0.001, respectively). Our study confirms that MPI obtained by TDI seems to be an early sensitive parameter of cardiac dysfunction in beta-TM. We concluded that MPI obtained by TDI may be an adjunctive parameter to conventional echocardiography for detecting early myocardial damage.