Severe intrauterine cardiac failure due to supraventricular tachycardia in a 29 week fetus was diagnosed using 2 dimensional and Doppler echocardiography. The prenatal tachycardia was successfully treated, the postnatal finding suggested Wolff-Parkinson-White syndrome. The fetal echocardiography by providing information on cardiac structure and haemodynamics may provide diagnostic and therapeutic useful informations. For the optimal pre- and perinatal management of this life-threatening condition absolutely essential a brief collaboration between the pediatric cardiologist and obstetricians.