Upper echelons theory is one of the most-researched theories in organizational science. It talks about top management team of an organization and their demographic factors as an indicator of the organization’s performance. This theory roots is sociology and psychology and applies cognitive factors in order to relate different demographic factors to choice making behavior of managers. However, despite its theoretical grounding and magnitude of research there is no specific study illustrating ontological and epistemological foundation of this theory. It is assumed that researchers implicitly applies these philosophical foundations in their research design but to contribute to this research strand this essay provides an introductory discussion on ontological and epistemological basis of upper echelons. Thus this essay falls under methodology and design category of social science research and aims to   provide its audiences a new set of insights into philosophical foundation of an organizational theory.