Calcification within active post-transplantation lymphoproliferative disorders has, to our knowledge, never been described. We report the case of a 14-month-old boy who presented 4 months after orthotopic liver transplantation with a primary calcification in a lymphoproliferative nodule involving the hepatic graft. This calcification was detected by routine ultrasonography, visible on plain radiographs, and the post-transplantation lymphoproliferative disorder was histologically proved.