Early initiation of effective antimicrobial therapy reduces morbidity and mortality. Annual institution-specific antimicrobial susceptibility tables or antibiograms can be used to guide empiric antimicrobial therapy and monitor resistance. This paper describes the development of an antibiogram for a metropolitan hospital based on the international standard CLSI M39 document. An antibiogram was created each year using positive blood cultures for the years 2009 to 2011, excluding coagulase-negative staphylococcus isolates which were assumed to be contaminants. Duplicate isolates within a 30-day interval were also excluded. Challenges included, for example, attaining all the relevant information from the laboratory information system in a usable format, and the need for significant manual manipulation of the data. The development of the antibiogram for our institution was driven by the pharmacy department as an initiative to improve appropriate and effective use of antimicrobials.