Background/Aims: The aim of the study was to investigate gastric emptying profiles in patients with postprandial distress syndrome (PDS) as a means to understand relationships between gastric emptying and dyspepsia. Methods: Gastric emptying times were measured using a 13C breath test. In addition to comparisons of 13C half excretion times (t 1/2 ex) between patients with PDS and healthy subjects, gastric emptying (%dose/h) curves were analyzed using a multipeak curve-fitting technique, and fitted curves were differentiated to measure the slope of curves for each time point. Results: (1) During the early postcibal period, the slope of %dose/h curves in 27% of patients with PDS was larger than the average slope derived from healthy subjects. The t 1/2 ex was also higher in these patients relative to healthy subjects. (2) During the midpostcibal period, the slope of %dose/h curves in 36% of PDS patients was larger than the average slope derived from healthy subjects. There was a trend toward lower t 1/2 ex values for these patients relative to control subjects. (3) When t 1/2 ex was calculated overall, however, there was no significant difference between healthy subjects and patients with PDS. Conclusion: Our findings document abnormal gastric outflow in patients with PDS. In some patients, there appears to be a significant correspondence between PDS-related dyspepsia and accelerated gastric emptying in the early postcibal period, whereas other patients showed a similar correspondence between dyspepsia and impaired inhibitory gastric emptying regulation in the midpostcibal period.