The finding of the frequent association in the infant of endothoracic tracheal compression and of GOR leads to discussion of their pathogenic link. In cases of endothoracic compression, manometric recording demonstrates the presence of an inversion of intragastric pressures with expiratory hyperpressure and a decrease in anti-reflux gradient. These data represent an argument in favour of medical anti-reflux treatment following discovery during endoscopic investigations for chronic or recurrent bronchopneumonia of the association of tracheal compression and gastrooesophageal reflux. Manometry should make it possible, where medical treatment proves unsatisfactory, to differentiate those cases where anti-reflux surgery is justified and those requiring a decompression procedure.