Continuous oesophageal pH measurements have been used to assess the influence of posture (lying, sitting, bed-up) on gastro-oesophageal reflux. The percentage of time during which oesophageal pH was below 5 and the number of reflux episodes was significantly reduced when patients were in bed-up position than when sitting or lying. There was no significant difference when sitting and lying positions were compared. The results suggest that by adopting the bed-up position (elevation of the head end of the bed with blocks of 28 cm), the patient will have a symptomatic benefit, the frequency of reflux is decreased, and acid clearing is improved.