This article describes a statistical method used to determine the minimum number of OR teams that should be on call for urgent procedures, in-house versus on standby from home, to minimize labor costs. The OR manager obtains the number of ORs staffed at each hour of the 24-hour period of interest (eg, 7 AM Saturday to 7 AM Sunday) from the surgical suite's information system. The minimum number of total staffed hours needed to care for patients is calculated for a prespecified level of the acceptable risk of inadequate staffing. A method used to determine whether each staff member should work in-house or on standby from home then is introduced. This method enumerates all possible combinations of shifts to find the one with the lowest cost, and it ensures a prespecified service level. An example based on 248 weeks of data collected from a large surgical suite is presented, and staffing for emergency procedures is reviewed. AORN J 74 (Nov 2001) 664–671.