The following article deals with the main causes of irrational decision making process in companies and with respective solutions to make decisions more rational and effective. With the aid of relevant literature, the ways managers, groups and leaders make decisions in reality will be clarified. Besides, the solutions to rational decisions examined through the perspective of managers, leaders and groups. Thus, the background of this article is the question “Are companies in control of their own decisions?” In addition, this paper includes relevant information about the features of decision making process, basic types of decisions, describes the most essential approach in management regarding to decision making and presents the top worst and best business decisions of all time.