We report three cases of left ventricular aneurysm diagnosed prenatally and followed by fetal Doppler echocardiography. A review of the literature reveals a paucity of information about this rare cardiac malformation. Most of the described cases (6 out of 9) have remained asymptomatic during pregnancy and after birth. Our cases, in contrast, and three others in the literature, had an ominous prognosis presenting cardiac failure initially or during follow up and showing a dynamic evolution of the aneurysm. Cross-sectional echocardiography provides the diagnosis, revealing the thin-walled aneurysm, usually apical, to be connected by a broad neck to the left ventricle. Color and pulsed Doppler shows low velocity and to-and-fro flow in the aneurysm. Sequential fetal Doppler echocardiography detects the potential growth of the aneurysm relative to ventricular size, revealing any compromise of cardiac performance by a decreased mitral opening, reversed atrial shunting, a hypokinetic infero-posterior left ventricular wall, and a poor systolic thickening of the wall of the aneurysm. Compromise of cardiac function, and deleterious impact on development of the lungs during fetal life, may depend on the early onset, growth and location of the aneurysm,which may occupy most of the fetal chest. We discuss issues of prenatal diagnosis, sequential surveillance of the natural history, and factors of prognosis as well as myocardial histological data from one of our cases.