The major goal of this review is to assess food risks of the introduction of genetically modified (GM) crops. The author analyzes the properties of the several classes of target proteins used in the transgenic constructions and discusses the problems that arise due to the pleiotropic action of transgenic proteins, the horizontal transfer of the transgenic constructions, primarily in bacteria, and their instability. Particular consideration is given to elevated risks of using the GM plant varieties for producing pharmaceutical preparations, due to the probability of uncontrolled cross-pollination between the GM plants and the plants grown for foodstuff production. The author emphasizes the requirement for assessing in detail all hypothetic risks in each particular case of cultivating GM varieties; as a control, such assessment must involve a comprehensive comparison with the conventional parental forms.