Ideal healthcare depends not only on how much money is expended, but on how effectively the money is allocated for a given resource. In anaesthesia, isoflurane, sevoflurane and desflurane are the most commonly used volatile agents accounting for largest expenditure in the operating room (OR) pharmacy budget. Operational costs of these volatile agents are determined by their respective acquisition costs, the fresh gas flow (FGF) rate used for agent delivery, and the number of volatile agent general anaesthetic hours. These determinants represent an opportunity to deliver significant cost savings through pharmacoeconomic modeling.