Background: Pediatric physicians regularly face the problem of uncertain procedural anticoagulation in children, especially in neonates. We sought to evaluate the safety, plasma concentration (pharmacokinetics, PK), pharmacodynamics (PD), and dosing guidelines of bivalirudin when used as a procedural anticoagulant in pediatric percutaneous intravascular procedures. Methods and Results: Pediatric subjects undergoing percutaneous intravascular procedures for congenital heart disease were enrolled and received the current weight-based dose used in percutaneous coronary interventions (0.75 mg/kg bolus, 1.75 mg/kg/hr infusion). Blood samples for PK/PD analyses were drawn, and safety was evaluated by monitoring bleeding and thrombosis events. A total of 110 patients (11 neonates, 33 infants, 32 young children, and 34 older children) were enrolled; 106 patients received the protocol dose. The PK/PD response of bivalirudin was predictable and behaved in a manner similar to that in adults. Weight-normalized bivalirudin clearance rates were more rapid in neonates and decreased with increasing age. Bivalirudin concentrations were slightly lower in neonates, with a trend to an increase with age. Activating clotting time response was consistent with adult studies and prolonged in all age groups, and there was reasonable correlation between activating clotting time and bivalirudin plasma concentrations across all age groups. There were few major bleeding (2 of 110, 1.8%) or thrombotic events (9 of 110, 8.2%) reported. Conclusions: PK/PD response of bivalirudin in the pediatric population is predictable and behaves in a manner similar to that in adults. Using adult dosing, bivalirudin safely provided the expected anticoagulant effect in the pediatric population undergoing intravascular procedures for congenital heart disease.