The aim of this study was to observe the effects of the position of the tracheal tube on cardiac performance or sedation requirements after cardiac surgery. There were no significant differences in heart rate, systolic blood pressure, or rate-pressure product during the first 16 hours postoperatively when 41 orally intubated patients were compared with 32 patients who were reintubated nasally. The two groups received similar amounts of sedative drugs postoperatively. During attempted nasal intubation, bleeding developed in four patients, and in three of these and four others the tube could not be passed. Failed nasal intubation gave rise to nasal discomfort in three of seven patients. Orally intubated patients complained more often of sore throat after extubation, whereas those who had been nasally intubated complained of discomfort in the nose and throat. We conclude that nasal re-intubation carries no advantage over oral intubation for ventilation after cardiac surgery.