Forty-five subjects with healed duodenal ulcer were administered either a placebo or a low-dose or high-dose regimen of misoprostol, a synthetic PGE₁ analog, in a doubleblind, random, parallel-group design to assess the effect of this prostaglandin compound on the gastric emptying of liquid-solid meals. A dual-radionuclide technique to measure liquid-and solid-phase gastric emptying rates of physiological meals by external gamma camera imaging was used. All subjects had a pretreatment control (baseline) evaluation, followed one week later by a treatment-influenced emptying study. The results demonstrated that misoprostol did not significantly alter gastric emptying of either liquids or solids; however, these results cannot be extrapolated to other prostaglandin compounds because of the diverse and sometimes paradoxical effects of different prostaglandins on gastric motility.