Human society has entered a new big phase in its own development at the beginning of this millennium, primarily thanks to the advancement of information and communication technologies. This new phase in the development of human society, among other things, is colloquially called the age of knowledge. This phase is characterized by growth in volume, but also the need for information and knowledge, which has resulted in significant strengthening of communication flows, making the world a global village with simultaneous growth of information but also knowledge and self-awareness of people. In those conditions, business entities, especially large ones, are significantly exposed to global competition, leading to a sizeable drop in margins influenced by supply and demand, thus increasing the risks of staying afloat for such entities. Namely, the management of such businesses requires high efficiency because there is little room for error, and the consequences of bad decisions can be fatal and endanger their survival. For this very reason, business practices are applying increased pressure on science to find a decision model that will ensure management quality and efficiency in decision-making. Large business entities in Croatia find themselves in a particularly complex situation which, along with the usual problems caused by academia, also deal with the problems caused by an economically unstable and extremely dynamic national environment whose centers of political powers have a significant negative impact. In order to assist large business entities, especially those from the Republic of Croatia and provide the concept of quality and efficient decision-making, primary and secondary research has been conducted. Based on the results of the research, the principle optimal model of managerial decision-making in large businesses has been defined. The subject model is a kind of ''know-how'' management, a basic algorithm that indicates how to decide in order to make decision-making efficient and sound. The developed model balances the perspective and prospective view of the future and optimizes components of rational and intuitive decision-making. Such a model is able to provide comparative advantage to those making said management decisions, and with it a competitive advantage for a business subject that operates in the complex conditions that define a modern society. Taking into account the requirements of business practice, the model can be seen as the initial platform on which the management of every large business entity needs to build its own relationship with the optimal decision-making process. Because of that, the model in question has both theoretical and pragmatic value.