A new method to distinguish oesophageal from tracheal intubation using the oesophageal detector device was evaluated. In 100 healthy adults, observers of differing experience reliably and rapidly detected 51 oesophageal and 49 tracheal intubations in a randomised, single-blind trial. In one case, blockage of the tracheal tube was detected swiftly and allowed corrective steps to be taken. This method can be used in patients with bronchospasm to detect correct tracheal placement when auscultation and decreased compliance of the chest may make clinical confirmation difficult. It can be concluded from this study that the oesophageal detector device is a reliable, rapid, inexpensive and easy to use method for the detection of oesophageal intubation and its very low cost should make it readily available in all situations where tracheal intubation is carried out.