Sleep disorder is a common medical problem. Sleep disorder has been associated with several diseases, including pulmonary disease, gastroesophageal reflux disease (GERD) and fibromyalgia. Interest in sleep phenomenology and gastrointestinal functioning has recently increased, because sleep disorder causes significant morbidity, as evidenced by the increased need for general medical and mental health treatment for emotional problems. A number of studies have found an association between sleep disorders and functional gastrointestinal (GI) disorders. Although arousal from sleep serves several protective roles, such as increase in the speed of esophageal clearance and in airway refluxes to prevent aspiration, awakening from sleep unfortunately induces impairment of sleep quality. Some investigations about the relationship between psychogenic factors and gut motility are controversial. In addition, reports of alterations in gut motility during sleep have also been contradictory. We have evaluated sleep disorder in functional dyspepsia (FD) patients using Pittsburgh Sleep Quality Index (PSQI) score. In our recent data, PSQI score of FD patients was significantly higher compared to that in healthy volunteers. Another study has reported that the distribution of subjects who thought that they got enough sleep was significantly lower for the FD/irritable bowel syndrome (IBS) subjects than for control subjects. Several studies have reported that anti-acid therapy and prokinetic agents are effective for certain FD patients. In addition, previous study has reported tricyclic antidepressants (TCA) drugs are effective for some FD patients. Finally, new drug, actiamide, a muscarinic antagonist and cholinesterase inhibitor, significantly improves Postprandial Distress Syndrome (PDS) symptoms. It might be critical issues for determination of precise mechanism for functional gastrointestinal disorders to clarify the relationship between gut motility and sleep disorders.