The effect on gastric emptying rate (GER) of elevated plasma glucose was investigated in eight healthy non-diabetics. They received intravenous infusions of 1000 ml 10% glucose (555 mmol, 1720 kJ) in 2 h: one-half before and the rest during the measure of GER. A control group was established with infusion of hypertonic sodium chloride and in a third group the GER was measured twice without infusion. GER was measured after 6 h of fasting, and following ingestion of a 100 g omelette (1400 kJ) tagged with 40 MBq 99mTc-sulphur colloid and 150 ml water with 8 MBq 111In-DPTA. Anterior and posterior recordings were made on gamma camera every 10th min during 1 h. Time-activity curves from the gastric area were generated for solid and liquid phases, respectively, using geometric means. The GER of solids was delayed, at least partly, by prolongation of the lag phase, and the GER of liquids was delayed following the intravenous infusion of glucose. The GER of solids was delayed following hypertonic saline infusion but not to the same extent as followed glucose in spite of the double osmotic load of saline. The percentage delay of GER of solids following glucose infusion was related to the increase in plasma glucose.