OBJECTIVE--To compare the reconstructions obtained by three dimensional echocardiography with the anatomical specimens used to generate the echocardiograms. DESIGN--The heart specimens were immersed in a water bath and imaged with a 5 MHz echocardiographic transducer mounted into a scan frame which allowed the transducer to travel a total distance of 4.4 cm in steps of 0.25 mm. The transducer records a tomographic slice at each incremental level thus producing 176 parallel slices of the heart to form the dataset. Reconstruction of the anatomical structures of the heart in a three dimensional format is achieved by means of different grey scales. MATERIALS--72 specimens of either normal or various congenitally malformed hearts. RESULTS--Good quality echocardiographic pictures were obtained, permitting three dimensional reconstructions in each heart. The cardiac chambers and valves could be displayed in a three dimensional format which accurately displayed the internal anatomy of the specimens. No artefacts, such as spurious septal defects, were produced in specimens with intact septums. The atrioventricular valvar leaflets, however, appeared thicker in the images than they were in the specimens. CONCLUSIONS--Three dimensional echocardiography accurately displays the anatomy of normal and congenitally malformed hearts.