Objectives: Radiofrequency of mobile phones may affect biological systems by increasing free radicals and by changing the antioxidant defense systems of tissues, thus leading to oxidative stress. L-cysteine, as a glutathione precursor, has an antioxidant property that may prevent oxidative damage to normal cellular processes. Methods: The effect of different concentrations of parentral L-CyS-HCl against harmful effects of EMR on rats' blood was studied namely: hematological parameters (osmotic fragility and blood picture), and biochemical parameters (reduced glutathione and malondialdehyde levels). Results: The results revealed that 20 mg parenteral L-CyS-HCl showed high protection for EMR radiated rats against hemolysis. In addition, EMR radiated rats received 20 mg parenteral L-CyS-HCl showed normal blood picture, GSH and Malondialdehyde levels, compared to radiated untreated rats. Conclusion:Parenteral L-CyS-HCl can be used for protection against mobile phone hazards