One of the fundamental public health challenges in the 21st century should be the improvement of people's health literacy, namely the understanding of health messages. The acquired high level of health literacy means that one knows how and where information concerning health determinants can be found, is able to assess it critically and in favorable conditions even modify them, which seems to be of particular importance from the perspective of heath promotion, prevention or treatment of diseases. Therefore, for professionals in these fields, knowledge of ways how to improve health literacy, as well as awareness of related benefits and the consequences of its poor level, seems to be indispensable. Thus, the aim of this paper is to explain the term of "health literacy",its determinants and implications. Med Pr 2009;60(5):427-437