With the increasing incidence of venous thromboembolic events in children, there has also been a concurrent increase in the use of anticoagulants in children. It is imperative that dosing recommendations of anticoagulants be derived from pharmacokinetic- and pharmacodynamic-based data in children and not simply extrapolated from data based on adults. Medications for children are often based on weight or body surface area, and are often distributed and metabolized differently as well. Furthermore, the hemostatic system in neonates and infants differs from that of older children and adults, and targets for therapy may differ. For these reasons, dosing guidelines for all antithrombotic medications should be based on pharmacokinetic and pharmacodynamic data. The authors reviewed pharmacokinetic and pharmacodynamic studies of anticoagulants in children and make dosing recommendations based on study findings.