Controversy exists about the occurrence of a gender-related difference in gastric emptying in humans. In this paper, a strictly standardized scintigraphic method, in which pancakes were labeled with technetium-99m-macroaggregated albumin, was used to follow gastric emptying in 16 male and 14 female healthy young subjects. The resulting mean gastric emptying curves described biphasic patterns. There was a similar lag period (30.6 +/- 4.2 vs 33.6 +/- 3.8 min; means +/- SEM) but a faster linear gastric emptying rate (32.9 +/- 1.4 vs 22.0 +/- 1.3%/hr), a shorter half-emptying time (111.2 +/- 8.6 vs 158.2 +/- 6.4 min) and lower residual radioactivity after 2 hr (43.0 +/- 3.5 vs 62.8 +/- 1.7%) in the male subgroup as compared with the female subgroup. The differences were highly statistically significant. As a result, separate reference values are recommended for young male and fertile female subjects.