A survey of antibiotic resistance in Australian states was undertaken by the Microbiology Quality Assurance Program of the Royal College of Pathologists of Australasia. Data were obtained from hospitals and private pathology laboratories serving both in-patients and out-patients at community hospitals. The study showed that resistance varied from state to state; it was highest in the Eastern states of New South Wales, Victoria, and Queensland, and lowest in Tasmania and Western Australia. In South Australia, isolates of Escherichia coli demonstrated a high degree of cefoxitin resistance. Western Australia and Tasmania showed high levels of gentamicin resistance for Klebsiella spp., as well as trimethoprim resistance in Proteus mirabilis. The relationship between erythromycin resistance and clindamycin resistance also differed among various states. These studies demonstrated the activity of sulbactam/ampicillin against a wide variety of common pathogenic bacteria in which resistance was mediated by beta-lactamase.