The objectives of this study was to assess differences in gastric slow waves measured by a newly approved multi-channel electro gastro gram (EGG) device between patients with functional dyspepsia (FD) and healthy controls. Materials and Methods: Gastric myoelectrical activity was measured by multi-channel EGG for 1 hour pre-prandial and for 2 hours postprandially in 72 FD patients and 16 healthy volunteers. Computerized spectral analysis methods were utilized to compute various EGG parameters. Results: 1) Multi-channel EGG was abnormal in 83.3% of patients. 2) The regularity of the gastric slow wave was significantly lower in the FD patients in both fasting and fed states; the lowest regularity was seen in channel 3. 3) There was a significantly higher incidence of arrhythmia and tachygastria in FD patients. The highest percentage of arrhythmia and tachygastria were both seen in channel 3. 4) The FD patients showed a significantly lower percentage of slow wave coupling among the 4-channel EGGs in the fed state. 5) The postprandial-pre-prandial power ratio was significantly less in FD patients. 6) These patients had high symptom scores particularly to nausea, upper abdominal pain and bloating. However, no significant correlation was noted between the EGG parameters and the symptoms. Conclusions: Gastric myoelectrical activity is impaired in most patients with FD. The impairment is reflected as a decreased percentage of normal slow waves and an excessive amount of arrhythmia as well as an abnormal spatial distribution of EGG parameters among the four channels, suggesting an impaired coordination of gastric slow waves.