One of the basic pillars of properly set up marketing communication is customer orientation - defining their essentials and preferences. As such, there is a need to detect the characteristics influencing the purchase decisions of consumers, especially Millennials as the current most valuable customer group for most companies. This paper therefore deals with the identification of characteristics determining the Millennial generation on the Czech market. Within the theoretical discussion, the basic background of segmentation and the Millennials are described. Exploratory factor analysis is used to process the primary data from a questionnaire survey with 976 participants. The results show that it is possible to identify these consumers according to four psychographic characteristics, namely in relation to ecology, lifestyle, traditionality, and sociability. Additionally, the behavioural characteristics defining Millennials from the point of view of cell phone usage, ways of purchasing, attitude towards marketing communication tools and use of marketing communication tools were identified. Each of these characteristics determines the Czech Millennials during their purchase decision-making process in depth.