Our basic premise is that organizations are best served by the inherent diversity of perspectives provided by separate public relations and marketing functions. Theory developed in the IABC Excellence Project shows that public relations makes an organization more effective when it identifies strategic constituencies in the environment and then develops communication programmes to build long-term, trusting relationships with them. Participation in strategic management provides the integrating link for public relations in enhancing organizational effectiveness. To provide its unique contribution, however, public relations must be separate from other management functions. However, communication programmes should be integrated or coordinated by a public relations department and that department should have a matrix arrangement with other departments it serves. Therefore, we advocate integrated marketing communication of advertising and marketing public relations. We add that an integrated marketing communication programme should be coordinated through the broader public relations function. Data are presented from the Excellence study confirming that public relations is most excellent when it is strategic and when marketing does not dominate public relations. However, public relations was equally excellent when housed in a single department or in specialized communication departments. Beyond structure, we add that marketing communication theories, if applied by an integrated department, differ in important ways from public relations theory and that discussion and research are needed to resolve these differences and to integrate the theories into a broader communication theory.