Contrast echocardiography is described as an important technique for the diagnosis of the anomalies of the venous system. Six patients with intrahepatic interruption of the inferior vena cava (IVC), ten patients with persistent left superior vena cava (PLSVC) connecting to coronary sinus (CS), one patient with PLSVC connecting to left atrium (LA) and ten patients, control group, with normal venous connections were studied by two-dimensional echocardiography; the injections of dextrose were made into the left hand, right hand, leg; the locations of the transducer were: subcostal position, parasternal and suprasternal. All patients underwent cardiac catheterization and cineangiography. When the injection was made into a leg vein, in the patients with infrahepatic interruption of the IVC we observed the contrast medium descending from the superior vena cava into the right atrium (RA). In the cases with PLSVC connecting to CS, contrast medium injected into the left hand, the sequential clouding of CS, RA and right ventricle was seen. The pattern of opacification in the case of PLSVC connecting to LA is discussed. In conclusion, contrast echocardiographic study of the connections of the venous system may be useful in planning the way for cardiac catheterization and also for the diagnosis of some anomalies which might be mistaken even at the time of the hemodynamic study.