The interest in the issue of legal security nowadays is very big and has an upward trend. This issue is also present today in public discourse. However, it turns out that individual participants of this discourse have problems with clear defining the term ‘legal security’. Their understanding of this term is often intuitive or partial. Therefore, there is the importance of presentation of my point of view on the issue of legal security in a synthetic form. The aim of this article is presentation of the definition and structure of the concept of legal security. The worked out concept has its practical usefulness and may be helpful in explanation of numerous problems connected with the functioning of important legal principles and phenomena.