In this study we evaluated the possible protective effects of selenium (Se) on hematological and oxidative stress parameters in rats chronically treated with cisplatin (cisPt). Four groups of Wistar albino rats were examined: a control, untreated rats (I), rats treated with Se (II), rats treated with cisPt (III), and rats treated with Se and cisPt (IV). All animals were treated for 5 days successively and killed 24 h after the last treatment. Hematological and oxidative stress parameters were followed in whole blood and red blood cells (RBC). Results showed that the chronic application of Se was followed by a higher number of reticulocytes and platelets, increased lipid peroxidation and GSH content in the RBC. Cisplatin treatment induced depletion of RBC and platelet numbers and an elevation of the superoxide anion, nitrites and glutathione levels. Se and cisPt co-treatment was followed by an elevation of the hematological parameters and the recovery of the glutathione status when compared to the control and cisPt-treated rats.