The aim of the study was to investigate a possible effect of omeprazole on the characteristics of the gastric emptying of liquid and solid in healthy subjects. The study was performed as a double-blind crossover study and the gastric emptying studies were performed after 10 days of treatment with placebo or omeprazole 40 mg o.m. Omeprazole was without effect on the characteristics of liquid emptying or the lag phase of solid. It does, however, decrease the emptying rate of solid as the omeprazole group had a median half-time duration of the linear emptying period which had twice the duration of the corresponding figure in the placebo group.