We evaluate the efficacy and safety of percutaneous transhepatic (TH) venous access for interventional cardiac catheterization. A retrospective review of all TH therapeutic catheterizations between January 1994 and September 1998 was performed. Patient demographics, pre- and postcatheterization hemoglobin and liver function studies, and complications were evaluated. TH access was performed for 30 interventional catheterizations in 25 patients with a median age of 39 months (range, 1 day to 41 years) and weight of 13.2 kg (3.1-87.0 kg). Indications for TH access were bilateral obstructed femoral veins (n = 15), obstructed femoral veins and superior vena cava (n = 3), Greenfield filter (n = 2), and presumptive improved route for intervention via TH access (n = 5). TH interventions were successful in 29/30 procedures (97%). Interventions via TH sheath sizes of 4-14 Fr included pulmonary angioplasty +/- stent (n = 11), radiofrequency ablation (n = 4), atrial septal defect device occlusion (n = 2), coil occlusion of pulmonary artery pseduoaneurysm (n = 2), Fontan fenestration device occlusion (n = 2), pulmonary valvuloplasty (n = 2), stent dilation of the superior vena cava (n = 2), and one each of device retrieval, Fontan baffle stent placement and subsequent redilation, Fontan fenestration dilation, transseptal mitral valvuloplasty, and cardiac biopsy. There were no changes in pre- and post-TH hemoglobin levels (mean +/- SD, 12.9+/-2.2 vs. 11.9+/-1.9 gm/dL; P = NS) or alanine transferase (34.0+/-27.5 vs. 43.4+/-18.2 IU/L; P = NS). One patient developed important intraperitoneal bleeding and required exploratory laporatomy. Percutaneous TH access is safe and effective as a route for interventional catheter procedures for patients with limited venous access.