Much of the extant research into why companies disclose environmental information in the annual report indicates that legitimacy theory is one of the more probable explanations for the increase in environmental disclosures since the early 1980s. Legitimacy theory is based on the idea that in order to continue operating successfully, corporations must act within the bounds of what society identifies as socially acceptable behaviour. The purpose of the practical research undertaken and reported in this paper is to extend the applicability and predictive power of legitimacy theory by investigating to what extent annual report disclosures are interrelated to: attempts to gain, maintain and repair legitimacy; and the choice of specific legitimation tactics. The quasi-experimental method adopted utilised semi-structured interviews with senior personnel from three large Australian public companies. The findings indicated support for legitimacy theory as an explanatory factor for environmental disclosures. Moreover, findings about the likelihood of specific micro-legitimation tactics being used in response to legitimacy threatening environmental issues/events, and dependent on whether the purpose of the response is designed to gain, maintain or repair legitimacy, are reported.