Achievements of genetics and molecular biology over recent decades have brought new opportunities such as possibility to modify the genotype of organisms by biomanipulation. Th ose opportunities have been used in medicine, the pharmaceutical industry and the practice of breeding plants and animals. Since the beginning they aroused enthusiasm but also raised concerns. GMO technology applied in relation to micro-organisms which are used in the industry or pharmacy, generally don’t raise any controversy because GMOs are being held in a closed circuit and don’t leak into the environment. Concerns are starting to appear when genetic modifi cations concern crops and livestock. GMOs enters then to food production, which takes place in the natural environment. This article is dedicated to a few selected problems that are part of more complex issues associated with the introduction of large-scale cultivation of genetically modifi ed organisms (GMO). In addition to issues directly concerning GMO, there are also issues presented that relate to the benefi ts and risks that GMO poses or may pose to human health and the environment. Questions have been raised whether the new food – genetically modifi ed food, satisfi es the conditions of environmental safety and health.