Continuous wave Doppler recordings of the turbulent jet through the restrictive orifice of a left atrial partition in a patient with corrected transposition of the great arteries and cor triatriatum showed alternate bands of high intensity diastolic and low intensity systolic signals with preservation of the normal configuration of the diastolic E and A peaks. It is thought that Doppler studies in cor triatriatum will provide useful complementary haemodynamic information in the echocardiographic diagnosis of this anomaly.