In patients with borderline left hearts or a severe left ventricular outflow tract obstruction, hybrid palliation can be used to stabilize the patient and postpone biventricular repair (BVR). In this study, we analysed growth of left-sided structures and outcomes of these patients. We conducted a retrospective cohort study including patients who received hybrid palliation between January 2010 and September 2023. Echo measurements were collected at hybrid palliation, BVR and last follow-up. Growth of left ventricular structures were analysed. In 38 patients, hybrid palliation was used to promote growth of left ventricular structures. In total, 15 patients received a Ross-Konno/Yasui procedure, while 23 patients received conventional BVR. In patients with a conventional BVR, a significant increase was found in left ventricular volume indexed by body surface area, Z-score of aortic valve and left ventricular outflow tract between hybrid palliation and BVR. Mitral valve Z-score did not increase significantly. After BVR until follow-up, only increase of the aortic valve Z-scores and left ventricular volume indexed by body surface area was found significant. Of all included patients (n = 38), additional surgical procedures were necessary in 8 patients during the interstage period and 15 patients after BVR. Additional catheter interventions were needed in 14 patients in the interstage period and 15 after BVR. Six patients died, with no mortality in the conventional BVR group. Hybrid palliation as part of a staged BVR is a safe and effective initial step and promotes the growth of left ventricular structures in patients with small left-sided heart structures. Close follow-up is mandatory because extra catheter or surgical interventions are frequently needed.