Guidelines regarding antimicrobial stewardship programs recommend an infectious diseases-trained physician and an infectious diseases-trained pharmacist as core members. Inclusion of clinical microbiologists, infection-control practitioners, information systems experts and hospital epidemiologists is considered optimal. Recommended stewardship interventions include prospective audit and intervention, formulary restriction, education, guideline development, clinical pathway development, antimicrobial order forms and the de-escalation of therapy. The primary outcome associated with these interventions has been the associated cost savings; however, few published investigations have taken into account the overall cost of the intervention. Over the past 5 years, there has been an increased focus upon interventions intended to decrease bacterial resistance or reduce superinfection, including infections associated with Clostridium difficile colitis. Few programs have been associated with a reduction in antimicrobial drug adverse events. Antimicrobial stewardship programs are becoming increasingly associated with clear benefits and will be integral in the in-patient healthcare setting.