Advances in fetal cardiac ultrasound technologies and refinements in cardiac catheterization techniques have made fetal cardiac intervention a reasonable option for fetuses with cardiac abnormalities such as fetal aortic stenosis and fetal hypoplastic left heart syndrome. These procedures — fetal aortic balloon valvuloplasty and fetal atrial stenting — are performed on the physical body of the mother for the benefit of the fetus, and yet carry risks to both mother and fetus. This paper reviews the ethics of fetal cardiac intervention in fetal left heart disease. It provides the ethical underpinnings for the development and performance of these procedures and outlines a practical ethical framework for counselling families in the face or these cardiac abnormalities. There is a need for careful case selection and a need to review these cases after fetal cardiac intervention. The establishment of registries to collect pre-procedural data and to monitor short and long-term procedural outcomes is expected to strengthen the evidence for ethical decision-making.