The effect of cigarette smoking on gastric emptying (GE) of a radio-labelled solid meal was examined in 14 patients with type I gastric ulcer diagnosed at endoscopy. The patients underwent GE measurement thrice: under basal conditions and for two smoking sessions--without and after cimetidine pretreatment (2 x 400 mg orally for 2 days and 400 mg orally 1.5 h before the isotopic GE examination). Cigarette smoking significantly delayed GE--the median GE index, Ix: 0.688 min-1.10-2 (range 0.033-1.886) after smoking vs. 1.246 min-1.-2 (range 0.384-2.339) under basal conditions, p less than 0.01. The inhibitory effect of smoking on solid GE was blunted when smoking coincided with cimetidine pretreatment--the median Ix amounted to 1.069 min-1.10-2 (range 0.022-1.462) and was not significantly different from that under basal conditions.