Rectus sheath hematoma results from the rupture of rectus muscle vessels by trauma, coagulation disorders or anticoagulant therapy, but it can occur spontaneously too. Its prognosis is good. On the other hand, posttransplant lymphoproliferative disorders (PTLD) are serious and potentially fatal complications in transplant recipients. Patients with PTLD have a mononucleosis-like syndrome or develop extranodal masses which involve various organs. We report the case of a renal transplant recipient who develop a rectus sheath hematoma as the first clinical feature of PTLD.