The aim of this study was to evaluate the diagnostic utility of cardiac catheterization and the efficacy of transcatheter intervention in patients with hemoptysis. Background: Cardiac catheterization may play a role in identifying the etiologies of hemoptysis with the potential for transcatheter intervention. Methods: This was a retrospective study of all the patients who were brought to the pediatric cardiac catheterization laboratory for the indication of hemoptysis over a 15-year period (2006)(2007)(2008)(2009)(2010)(2011)(2012)(2013)(2014)(2015)(2016)(2017)(2018)(2019)(2020).Results: Twenty-one patients underwent 28 cardiac catheterizations. The median age was 17.4 years (range 0.3-60.0 years), and the underlying cardiac diagnoses were normal heart n = 3, pulmonary hypertension 1, heart transplant 1, pulmonary arteriovenous malformation 1, pulmonary vein disease 3, biventricular congenital heart diseases 5, and single ventricles 7. The diagnostic utility of catheterization was 81% (17/21). At two-thirds (18/28) of catheterizations, transcatheter interventions were performed in 14/21 (67%) patients: aortopulmonary collateral embolization 14, aortopulmonary and veno-venous collateral embolization 1, and pulmonary arteriovenous malformation embolization 3. Although recurrent hemoptysis was frequent (50%) post-intervention, the final effectiveness of transcatheter interventions was 79% (11/14 patients). Overall mortality was 19% (4/21), all in those presenting with massive hemoptysis. Conclusions: Cardiac catheterization was shown to have good diagnostic utility for hemoptysis especially in patients with underlying congenital heart disease. Despite the high mortality and recurrent hemoptysis rate, transcatheter interventions were effective in our cohort.