This study aims to explain through institutional theory how organizations can acquire legitimacy by achieving harmonious appearance even when the structures and practices of organizations don't conform to the institutional environment. Therefore it is seeking the answer of the question that "the role of organizational language in organizational legitimacy can be explained by institutional theory?". In the investigation have been examined and analyzed that legitimacy seeking organizations, evaluators who have given legitimacy and the language strategies used by organizations to create this provision in evaluators. They have come to the conclusion that the organizations use in communicating with the evaluators language that they build with the symbols and words of the institutional structure, thus constituting a provision of legitimacy by affecting the pragmatic, cognitive, moral, value and emotional aspects of evaluators. This result shows that the relationship between organizational language and organizational legitimacy can be explained more clearly in terms of institutional theory because both are institutional phenomena.