Antimicrobial sensitivity testing serves two important purposes. The more immediate of these is to guide clinicians in the choice of appropriate antimicrobial therapy for individual patients. However, in many patients, treatment with antibiotics is initiated before the results of sensitivity tests are known. Empirical therapy ideally should be based upon a soundknowledge of prevalent local pathogens and their antibioticsensitivity patterns. Such knowledge depends upon the availabiltiy of data collected by the microbiologylaboratory. Even in small laboratories, periodic analysis of such data may reveal important insights into the epidemiology of antimicrobial resistance. In addition, the resulting summaries (antibiograms) can be used as educational tools and are essential in any attempt to influence prescribing habits (AU)