Congenital aortic stenosis is a rare cause of congestive heart failure and hydrops fetalis. This report describes a case of prenatally diagnosed critical aortic stenosis and endocardial fibroelastosis leading to a severe hydrops fetalis at 27 weeks of gestation. Successful transplacental digitalization was performed and all signs of hydrops resolved within 2 weeks. The pregnancy continued with normal development of the fetus and birth was induced at 39 weeks of gestation. After an uneventful vaginal birth, the child was transferred for cardiac catheterization, and balloon dilation of the aortic valve was performed successfully. Follow up at the age of 2 years showed only mild left ventricular cardiac hypertrophy, a moderate elevated pressure gradient of 50 mmHg at the aortic valve and mild aortic and mitral regurgitation. No further interventions were necessary at this point.