In a randomized crossover study, we compared the effect on gastroesophageal reflux of three sleeping positions: elevation of the head of the bed on standard eight-inch bed blocks; elevation by a foam wedge; or a flat position. Fifteen subjects with moderate to severe reflux symptoms were studied in each position on consecutive nights using continuous intraesophageal pH monitoring. We found no difference in reflux frequency among the positions. The wedge caused a statistically significant decrease in the time that distal esophageal pH was less than 4 as compared to the flat position. The wedge also decreased the longest episode experienced by the subjects. Elevation on blocks caused a similar improvement in parameters but failed in this study to achieve statistical significance. Both elevation by a wedge and on blocks showed a trend towards a decrease in clearance time as compared to the flat position. The patients did not always prefer elevation on a wedge, but for some it is a valuable alternative to elevation by bed blocks.