Entrepreneurship should be perceived as an element of an economic system. It also seems that it would be legitimate to include it in the institutional system of the economy. Entrepreneurship is not only determined by institutions of different character (institutional matrix) but it is an institution itself. The research undertaken by the author is aimed at analysing the essence of entrepreneurship in terms of institutional aspects. A specific character has determined the author's prospecting for the institutional nature of entrepreneurship. Entrepreneurship is the institution that determines many economic processes. We can say that entrepreneurship is crucial. This is particularly apparent when we look at entrepreneurship as a set of rules followed by everybody: company directors, chairpersons, managers and also employees. If we add this institutional aspect to the classical concept, entrepreneurship appears to be an individual principle determining action in market economy. Then, the view of entrepreneurship becomes complete. This is the missing element which best fits in with the puzzle and which holds different points of view together