Postsplenectomy portal vein thrombosis for hematological diseases is uncommon in the pediatric population. The case summarized is, to our knowledge, the first manifestation of portal vein thrombosis in a child after preoperative splenic artery embolization and subsequent splenectomy for severe hypersplenism. We suggest that early routine diagnosis by Doppler ultrasonography and subcutaneous low molecular weight heparin therapy are useful steps for a successful outcome.