This dissertation is a multi-method, institutional theoretic study that sought to understand how organizational communication in the United States petroleum industry functioned as a device for corporate legitimation over the years 1975-1990. The study investigated the symbolic dimension of organizational communication taking place via the medium of oil industry Annual Reports. The study addressed two major research questions: (i) What was the nature of corporate legitimation in the U.S. petroleum industry during the years 1975-1990? and (ii) What was the structure of corporate legitimation in the industry over these years? The context for these questions was provided by important industry-level actions such as business-government relations, diversification, OPEC relations, corporate restructuring, etc. To understand the nature of corporate legitimation, the study employed methods of grounded theory analysis. In addition to investigating the ideological characteristics of oil industry Chief Executive Officers' (CEOs') Letters to Shareholders, this analysis also focussed upon the linguistic devices of persuasion (e.g., myths, metaphors, etc.) and the processes of discursive closure employed in these letters. On the other hand, quantitative techniques of content analysis, including multivariate research methods such as factor analysis, discriminant analysis and MANOVAs, were employed for analyzing the structure of corporate legitimation. These analyses were designed to investigate the interrelationship of the various concepts by which oil industry CEOs expressed themselves in their Annual Reports. This study show that the U.S. oil industry employed eight inter-connected ideologies in the process of legitimating salient industry-level actions of these years. In part, the persuasive power of these ideologies derived from their ability to evoke certain mythic and taken-for-granted elements of the cultural 'common sense.' As regards the structure of corporate legitimation, an important finding of the study is that the industry's Annual Reports assumed four personae in the process of articulating their ideological messages. The study advances the thesis that corporate legitimation in an industry such as petroleum implies the legitimation of a given 'way of life,' and involves both expressing and constituting the subjectivities upon which this way of life depends. Finally, the study draws some implications for management research and practice.