Advances in supportive care have changed the landscape of clinical pediatrics from acute life-threatening conditions to more chronic diseases. Venous thromboembo-lism (VTE), comprising of deep venous and thrombosis (DVT) and pulmonary embolism (PE), traditionally considered as an acute and chronic disease of the elderly, is increasingly recognized in hospitalized children and has emerged as a significant public health burden. Although the incidence of pediatric thrombosis is lower than that in adults, over the last few decades it has been recognized that pediatric thrombosis has become a substantial health hazard and may be associated with significant morbidity and mortality. Additionally, the health-care burden of VTE may be particularly high for affected children, given the additional impact imposed on the child’s family members and by the much greater life expectancy compared with affected elderly adults. Evidence-based recommendations for management of pediatric thrombosis are still lacking, due to lack of large carefully conducted clinical trials and most recommendations are either directly extrapolated from adults or are based on consensus or expert opinions . As the incidence of pediatric thrombosis increases and newer anticoagulant drugs make their way into the clinical field, investigators have felt the necessity for improved diagnostic testing, risk adapted treatment regimens and better definitions of outcome measures after pediatric thrombosis . This chapter focuses on recent knowledge and current advances in pediatric extremity and caval thrombosis.