The electric activity of the esophagus was studied in 12 mongrel dogs by means of three electrodes introduced into the upper, middle, and lower third of the esophagus (electroesophagogram). The esophageal pressure was measured by a 6-Fr catheter with side ports. Pacesetter potentials (PPs) were recorded showing the same frequency, amplitude, and velocity of conduction from the three electrodes of each dog on all test days. Action potentials (APs) followed the PPs randomly and were associated with a rise in the intraesophageal pressure. Balloon distension effected an increase of the electric activity proximally to the balloon and a decrease distally. These changes were augmented with increasing balloon distension up to a volume of 20 ml beyond which no electric activity, or a ‘silent’ electroesophagogram, was registered. The caudad direction of PPs and APs was evidenced when after esophageal myotomy the potentials appeared proximally but not distally to the cut. This suggests also the presence of a pacemaker in the cervical esophagus which might initiate the PPs. In conclusion, the study demonstrates that the esophagus possesses an electric activity. It is hypothetized that a pacemaker in the cervical esophagus triggers the PPs which in turn initiate the APs. The latter are associated with esophageal motile activity which increases with balloon distension of the esophagus and might be responsible for transmission of food bolus along the esopha