evidence: Abstract: With the rapidly increasing number of artificial sources of electromagnetic fields, it needs research of their effects to living organisms. The most common object of these studies is primarily a human who is exposed to electromagnetic radiation in the environment, at home and at workplaces. In this area are also observed the changes in behavior of animals and plants caused by the high frequency electromagnetic radiation. Plants are very sensitive because they can perceive a lot of perceptions from the environment. In this article, we observed the effects of Wi-Fi radiation on the growth plants, namely garden cress. One sample was exposed to long-term electromagnetic radiation in the vicinity of Wi-Fi router. The second sample was exposed minimum to that radiation. It has been shown that long-term exposure of Wi-Fi radiation in the vicinity of the cress causes changes in growth and development as well as visible changes of discoloration and vitality. [...] The experiment has demonstrated the negative effects of Wi-Fi radiation on the plants of garden cress, but for the confirmation of that argument will be necessary to repeat this experiment. The result was the slowing of plants growth, physiological and metabolic changes and genetic mutations that can lead to death of the plants. It is therefore necessary to continue research this issue, to be able to more accurately describe the changes in plants caused by high-frequency electromagnetic fields.