Introduction. Electromagnetic radiation (EMR) that has an effect on living organisms may be a source of oxidative stress. A lack of proper compensation by antioxidant defences on the part of proteins leading to an uncontrolled growth of reactive forms of oxygen, which may give rise to numerous health conditions. Various scientific studies have indicated that propolis has multiple valuable medicinal properties: antibacterial, anti-inflammatory, antioxidant, protective - in relation to liver parenchyma, as well as anti-cancer. Nonetheless, the results of studies concerned with its antioxidant capabilities are not explicit and require further tests and analyses. Objective. Determination of the effect of propolis supplementation on selected oxidative stress parameters in blood platelets exposed to electromagnetic radiation mitted by LCD monitors. Material and methods. The material was a suspension containing human blood platelets. A 7% propolis solution was added to a cellular preparation before an exposure to EMR with a frequency of 1 kHz and an intensity of the electric component of 220 V/m (corresponding to sitting a distance of 15 cm from an LCD screen) for a total of 60 minutes. Before the exposure, as well as immediately following it, the researchers determined the level of activity of superoxide dismutase and malondialdehyde concentration, and evaluated it with regard to the control sample, i.e. material which was not subjected to EMR exposure.Results. Electromagnetic radiation caused a statistically significant decrease in superoxide dismutase activity as compared with the reference group, irrespective of propolis supplementation. All of the studied groups indicated a minimal increase in the malondialdehyde concentration as compared with its initial values; however, the differences were not statistically significant. Conclusions. The obtained results allow to conclude that the analysed electromagnetic radiation produced unfavourable changes in the activity of one of the enzymes responsible for antioxidative protection - superoxide dismutase (SOD - 1), and, moreover, a slight intensification in lipid peroxidation, which is expressed by an increase in malondialdehyde concentration (MDA). The supplementation with 7% propolis solution does not constitute sufficient protection against the negative effect of EMR. It is necessary to conduct further studies as well as determine the behaviour of other antioxidative enzymes.