A 3-month-old German shepherd puppy with a congenitally dilated oesophagus had radiographic, cinefluoroscopic, and oesophageal motility studies before a modified Heller operation was performed. Subsequent examination of the oesophagus revealed no ganglion cells, and the condition was considered to be identical with human achalasia. In dogs, this appears to be more common in the German shepherd breed.