U radu se razmatra kako se u okviru teorije organizacije konceptualiziraju pojmovi javnog i privatnog. Cilj je rada pokazati kako se s upravnim razvojem mijenjaju i pristupi razlikovanju javnih i privatnih organizacija. Uprava se razvija u smjeru sve većeg približavanja javnog i privatnog sektora. Taj je razvoj uvjetovao i redefiniranje pojmova javne i privatne organizacije. Tradicionalno javne organizacije bile su definirane kao javne, a privatne kao privatne, prema formalnom, pravnom kriteriju vlasništva: organizacije u vlasništvu države smatrane su javnima, organizacije u vlasništvu privatnog aktera, privatnima. Suvremeni razvoj uprave doveo je u pitanje ovu formulu, stoga se danas mogu identificirati četiri pristupa u definiranju „javnosti“ organizacije: najstariji formalni, zatim dimenzionalni, normativni i integrativni. This paper is concerned with the issue of public – private divide within the theory of organization. The main argument is that with administrative development and change, the definition of public, as opposed to private organization, also changes. Current state of public administration is characterized by the blurring of boundaries between public and private sectors. Due to such development the approach to public – private distinction had change. Traditionally, public organizations were identified as public on the basis of formal, legal criteria of ownership: organizations in the property of the state were considered public, and those in the private ownership, private. Modern public administration challenges this formula. Thus, it is possible to distinguish four approaches in the conceptualization of publicness of an organization: the oldest, formal approach, dimensional, normative and integrative approach.