Background: Erythropoietin (EPO) and its receptor play a major role in embryonic brain, are weakly expressed in normal postnatal/adult brain and up-regulated upon metabolic stress. EPO protects neurons from hypoxic/ ischemic injury. The objective of this trial is to study the safety and efficacy of recombinant human EPO (rhEPO) for treatment of ischemic stroke in man. Materials and Methods: The trial consisted of a safety part and an efficacy part. in the safety study, 13 patients received rhEPO intravenously (3.3 x 10(4) IU/50 m/130 min) once daily for the first 3 days after stroke. in the double-blind randomized proof-of-concept trial, 40 patients received either rhEPO or saline. Inclusion criteria were age