In the last three decades ultrasound investigation is used in cardiology. Especially in the last ten years it is not only possible to visualize cardiac anatomy and function by M-mode or 2-dimensional echocardiography but it is also possible to visualize the bloodflow velocity by continuous wave Doppler, single or multigate Doppler and 2-dimensional Doppler. The combination of the different modalities of ultrasound investigation of the heart gives us so much insight in cardiac anatomy and function that cardiac pathophysiology can be better understood and so invasive diagnostic procedures can be avoided, especially in children with congenital heart malformations. It is clear that not only the patient will benefit from this possibility but also the economical sources. In a 15 years review of our institution, where in 1976 2-dimensional echocardiography and in 1979 Doppler echocardiography has been introduced, it can be seen that ultrasound technique replaces invasive heart catheterization.