The suitability of a simple method of measuring the rate of gastric emptying of solids using 99mTc-marked filter paper pieces has been evaluated. In five healthy volunteers emptying of the filter paper pieces and of 198Au-tagged liver was measured simultaneously. In every proband the filter pieces left the stomach at a faster rate than the liver, but showed a linear emptying pattern in each experiment. Based on these observations and on recent results of other authors, a new concept of the gastric emptying of solids is presented. Within the framework of this model the use of the filter pieces in clinical studies to simulate a solid meal appears to be justified.