A new method for measuring the lateral wall pressure on the trachea from cuffs of endotracheal tubes is presented. The method is based on measuring the force necessary to force a small, constant flow of air through a Teflon or silicone rubber envelope, placed between the cuff and the tracheal wall. The pressures recorded are 0.1 to 0.3 kPa higher than the theoretically correct values. The response time is 0.28 s for 90% of full deflection. Dynamic recordings of the lateral wall pressure of high and low residual volume cuffs can be obtained for analysis of the interaction between the cuff and the tracheal compliance. No method for accurate, dynamic recording of the lateral wall cuff pressure has previously been published.