The effects of endotracheal tube cuff pressure upon the tracheal wall is well documented and researched. Hyperinflation causes mucosal damage subsequent to restricted capillary blood flow (Seegobin and Hasselt, 1984), and underinflation increases aspiration risk (Bernard et al, 1979). There are critical care areas with no method of obtaining accurately cuff pressure other than adopting the minimal occlusion technique, i.e. inserting just enough air into the cuff to prevent air leakage. Although this is a useful method for obtaining an adequate seal, it does not safeguard against hyperinflation. The aim of this study was to demonstrate that without accurate measurement of intracuff pressures of endotracheal tubes, pressure will be outside the normal recommended limits, which could place patients at risk. Accurate measurements of cuff pressures post cardiac surgery were recorded using a Malincrodt pressure gauge. Theatre staff and intensive care unit nursing staff were unaware of the study until its completion. It is concluded that cuff pressures are too high using the minimal occlusion technique and the cuffs are prone to leaking.