Gastric emptying of a digestible solid and liquid meal and oesophageal emptying of a solid bolus were measured with scintigraphic techniques in 20 randomly selected Type 2 (non-insulin-dependent) diabetic patients receiving oral hypoglycaemic therapy and 20 control subjects. In the diabetic patients, the relationships between oesophageal emptying, gastric emptying, gastrointestinal symptoms, autonomic nerve function and glycaemic control were examined. The percentage of the solid meal remaining in the stomach at 100 min (p less than 0.001), the 50% gastric emptying time for the liquid meal (p less than 0.05) and oesophageal emptying (p less than 0.05) were slower in the diabetic patients compared to the control subjects. Scores for upper gastrointestinal symptoms and autonomic nerve dysfunction did not correlate significantly (p greater than 0.05) with oesophageal, or gastric emptying. The 50% gastric emptying time for the liquid meal was positively related (r = 0.58, p less than 0.01) to the plasma glucose concentration at the time of the performance of the gastric emptying test and the lag period, before any solid food emptied from the stomach, was longer (p less than 0.05) in subjects with plasma glucose concentrations during the gastric emptying measurement greater than the median, compared to those with glucose concentrations below the median. These results indicate that delayed gastric and oesophageal emptying occur frequently in Type 2 diabetes mellitus and that delayed gastric emptying relates, at least in part, to plasma glucose concentrations.