In a prospective investigation, a relatively low overall sensitivity of radiologic investigation for reflux esophagitis was found (62%). There was, however, a difference between the various stages: in grade I esophagitis the sensitivity was 50%, in grade II 71% and in grade IV 100%. The importance of observation of thickened folds for low-grade esophagitis is emphasized. In addition, the probability of reflux esophagitis in the absence of hiatus hernia was found to be low. In any patient referred for a barium meal attention should also be paid to the lower esophagus.