Our objective was to investigate the correlation between gastric emptying and sensation in patients with functional dyspepsia (FD). Thirty patients with FD and 15 controls were studied. Proximal gastric compliance and sensation thresholds were measured with a barostat, and gastric emptying was assessed for 70 min after the ingestion of 500 ml of water using real-time ultrasonography. Results were as follows. (1) Patients showed a significantly longer half-time of gastric emptying than controls (30.03 +/- 8.20 vs. 23.07 +/- 4.67 min; P < 0.001). The sensation thresholds were significantly lower in patients than in controls based not only on pressure but on volume. However, there was no difference in gastric compliance between patients and controls. (2) The half-time of gastric emptying was correlated with various thresholds of sensation based on the volume (perception, r = -0.52, P < 0.005; discomfort, r = -0.54, P < 0.005; pain, r = -0.58, P < 0.005; maximal tolerance, r = -0.42, P < 0.005). But there was no significant correlation between gastric emptying and sensation thresholds based on pressure. Delayed gastric emptying and/or gastric hypersensitivity are present in more than 50% of FD patients. The coexistence of these two abnormalities is more common than the single impairment. There is a correlation between gastric emptying and visceral sensation to gastric distention in patients with FD.