Diagnostic and therapeutic interventional radiologic procedures that provide many treatment options in adults are gaining acceptance in pediatric medicine. Diagnostic (69 patients) and therapeutic (31 patients) interventional experiences in 100 children are summarized, and the procedures of choice for various clinical problems are outlined. Procedures include percutaneous biopsy for benign and malignant diseases, transhepatic cholangiography and biliary drainage, genitourinary procedures (nephrostomy, stent placement, balloon dilation), aspiration of fluid for laboratory analysis, therapeutic drainage of abscesses and noninfected fluid collections, and percutaneous gastrostomy and gastroenterostomy. Diagnoses were accurate in 96% of cases, and therapeutic procedures were successful in 84% of patients, usually obviating operation. Complications occurred in six patients (6%); the most severe was hemoptysis causing respiratory distress. There was no procedure-related mortality. Interventional procedures have wide applications in pediatric patients.