The management of respiratory infections is a complex and dynamic process, with many areas of controversy and numerous unresolved questions. In an apparent effort to deal with these issues, guidelines for care are being developed for a variety of infections including bronchitis, community-acquired pneumonia, hospital-acquired pneumonia, tuberculosis, HIV infection, and viral illness in immune-compromised patients. As the era of managed care approaches, guidelines will continue to emerge, and several questions about their utility must be answered. In this discussion, the rationale for the popularity of guidelines is examined, along with a review of the processes by which they are developed. Although evidence-based medicine has been suggested as a basis for this process, there are several problems with this approach. Most importantly, evidence-based medicine does not adequately allow for the incorporation of local experience, which is so vital in the management of respiratory infection because of the variability in bacteriology and antimicrobial susceptibilities in different practice settings. If a guideline is developed by a consensus of experts, and viewed as an hypothesis that can be modified based on local data collection, then it can be very useful and can lead to a number of potential benefits for patients with respiratory tract infection.