Upper-extremity deep venous thrombosis (UEDVT) is an increasingly important clinical problem in children. These events are classified as primary or secondary, with the latter being the most common and usually associated with the presence of a central venous line. Among primary UEDVT, the so-called Paget-Schroetter syndrome, effort-related or exercise-induced upper-extremity thrombotic event represents an extremely rare finding that has never been described in a pediatric series. The objective of the second part of this two-part article is to report the first pediatric series in a group of adolescents with this condition from a single center, describing their clinical features, management, and outcome. A retrospective chart review of 6 patients seen between December 2003 and April 2005 was conducted, with a median follow-up of 9 months (range 2–17). Four females and two males, all Caucasian, were enrolled with a median age of 16 years (range 14–17). In all cases, strenuous exercise was present in the month preceding diagnosis and mild trauma was present in only one case (weight lifting). At presentation, all patients had objective swelling of the affected limb for a median of 4 days (range 2–14), and 4 patients had UEDVT of the dominant arm. Thrombophilia investigation revealed that 50% had a combined prothrombotic state at presentation, and all patients were/are being treated with anticoagulation for 6 months (low-molecular-weight heparin followed by warfarin). Continuation of the initial symptoms was present in all cases but one at the 3-month clinic follow-up (last case has yet to reach 3 months of follow-up), and residual moderate to severe postthrombotic syndrome was present in all 3 cases followed for more than 12 months. Of those 3 patients followed for more than 1 year, 2 patients recurred despite having complete resolution of the thrombus after 6 months of anticoagulation, and the third patient underwent surgery with clinical improvement. Adolescents with UEDVT treated only with anticoagulation seem to have a poor outcome.