The article’s main subject matter is a historical presentation of formation process and evolution of the intelligence and counterintelligence agencies of the Second Republic of Poland, between the 1918 a 1939. The authors attempt to characterize, based on historical and contemporary sources and evaluated data, the structure, organization and general activities of the Polish intelligence and counterintelligence agency, in that period ending at the outset of WWII. In an effort to analyze specific intelligence agencies – the role they played in the state security system of the Second Republic of Poland, we can observe an evolvement of the intelligence sector of Poland being initiated by the patriots working previously for the independence movement’s organizations, also those, who were prior to Poland’s regaining independence the officers of foreign armies and security forces. And later were able to use acquired knowledge for the new organizational structures. However, relying especially on the Poland’s tradition of intelligence services prior to the loss of independence.