Use of selected systemic antimicrobial agents at Boston City Hospital (BCH) has been monitored by requiring that choice of those agents be justified to a member of the Infectious Diseases Unit before the agent is dispensed for use in a patient. The amounts of various antimicrobial agents and classes of agents used at BCH in 1972 differed considerably from amounts used in other hospitals where restraint was not employed. Whether these differences in usage led to better care for the patient could not be determined from the data presented. These aspects must be studied in greater detail to determine the benefits, if any, that may be derived from such surveillance and control, especially in view of recent proposals for implementation of "peer review" in this as well as other areas.