Critical aortic valve stenosis (CAVS) is a life-threatening cardiac disease of the newborn requiring urgent treatment. First-line therapy is still controversial. The aim of our study was (1) to analyze retrospectively the patients of our institution who underwent balloon aortic valvuloplasty (BAV) due to CAVS, and (2) to describe techniques for improved feasibility of the intervention using microcatheters and retrieval loops. Twelve patients underwent 23 BAVs: 1 BAV was performed in 3 patients, 2 BAVs in 7 patients, and 3 BAVs in 2 patients. Trans-valvular pressure gradient (Δp) and left ventricular shortening fraction (LVSF) improved significantly in the first two interventions; first BAV: Δp from 73.7 ±34.5 mmHg to 39.8 ±11.9 mmHg (p=0.003) and LVSF from 22.3 ± 13.5 % to 31.6 ±10.2 % (p=0.001); second BAV: Δp from 73.2 ±33.3 mmHg to 35.0 ± 20.2 mmHg (p<0.001) and LVSF from 26.7 ±9.6 % to 33.3 ±7.4 % (p=0.004). Cardiac surgery during the neonatal period was avoided for all children; median time to valve surgery was 5.75 years. Few complications occurred: mild to moderate aortic regurgitation, one remediable air embolism, and one intimal injury of the ascending aorta. We conclude that BAV is a successful primary treatment for CAVS resulting in left ventricular relief, stabilization of the neonate, and a time gain until cardiac surgery.