This study presents the results of an external communication audit of the National Tropical Botanical Garden (NTBG), a congressionally chartered nonprofit organization dedicated to the conservation of tropical plant diversity. Information was gathered during the communication audit through interviews with NTBG's key decision makers, content analyses of NTBG's primary publications, and a questionnaire measuring the public-organization relationship. The audit assesses NTBG's external communication policies, practices, capabilities, and needs in the context of systems theory and external relations strategic planning theories. The findings of the audit identify who NTBG considers its target publics and how well they are reaching certain audiences. The results also indicate in which areas NTBG's current communication system is meeting or not meeting the objectives of the organization. The study concludes with a series of recommendations for how NTBG can improve its external communication system.