The use of echocardiography in diagnosing intra-cardiac vegetations is described in two infants. The condition is unusual in infancy, but can be suspected from the clinical picture and positive blood cultures. Using echocardiography it is possible to localize the vegetations exactly and estimate the extent of valvular involvement. In one of the cases presented a vegetation on the anterior mitral leaflet was diagnosed and a gradual increase in size could be demonstrated. In the other case a large echo-producing mass was found attached to the tricuspid valve, protruding into the right ventricular outflow tract. This mass represented a fungal vegetation. In both cases autopsy later verified the echocardiographic findings.