British Nobel Prize-winning economist Ronald Harry Coase, the founder of the transaction cost theory, died on Sept. 2, 2013. Born in 1910 near London, Coase grew up, studied and then taught at a number of prestigious universities in Britain before moving to the United States in the 1950s. He is recognized to be the father of the transaction cost theory and an economist who managed to combine economics and law – two co-existing but not necessarily overlapping areas. His most famous publications included The Nature of the Firm from 1937 and The Problem of Social Cost from 1960. They raise two fundamental questions: “Why do companies exist? and “How to resolve the problem of externalities?” Coase will be remembered by economic history as a man who was not afraid to ask difficult questions, challenge traditional solutions and look for new answers. At the same time, he was well aware of his own imperfections. The article summarizes Coase’s achievements and outlines his most well known and influential work and concepts. The authors based their research on a literature review focusing on the influence Coase’s work had on different research areas – from the transaction cost theory and its impact on sector and company analysis to the issue of social cost and the discussion of its economic and ethical impact, to monopoly theory. Coase won the Nobel Prize for his work in economics in 1991.