It has been demonstrated that M and B mode echocardiography provides anatomical and functional information regarding the fetal heart although it's usefulness is limited. Employing a high resolution system, we studied the cardiac anatomy images as well as tomographic sections of the heart of human fetuses. Thirty fetuses, 19-41 weeks, were studied through tomographic sections of the heart in long axis, short axis, apical and subxiphoid 4 chambers view. In all fetuses a view of the majority of the cardiac structures was obtained. The sections of apical and subxiphoid four chambers, short axis and long axis were obtained in 93%, 93%, 96% and 86% respectively. This anatomical views permitted detailed identification and analysis of the four cavities, atrio- ventricular, pulmonary and aortic valves, as well as the great arteries. The aortic arch, pulmonary bifurcation, the outlet of the inferior venae cavae, the superior venae cavae and the right atrium were poorly visualized. The spinal cord and the fetal ribs in older fetuses prevented us from seeing some structures, due to a greater development in the centers of ossification. Bidimentional echocardiography was performed in 77% of the fetuses after birth, in all of them cardiac anatomy before birth is possible, making the diagnosis of major malformations in utero more feasible.