Megaesophagus was diagnosed in 9 adult ferrets. Clinical history of the ferrets included regurgitation, difficulty in swallowing, partial anorexia, and lethargy. Cachexia, dehydration, weakness, and ptyalism were observed on physical examination. Radiography revealed the esophagus of each ferret to be dilated in the thoracic and cervical regions. Of 4 ferrets that had lymphocytopenia, 2 had concurrent leukopenia. Serum biochemical analysis revealed high activity of alanine transaminase (4 ferrets) and aspartate transaminase (3), and hypoglycemia (4). Treatment included administration of fluid, antibiotics, and agents directed against possible primary causes of megaesophagus. Treatments were ineffective, and all of the ferrets died or were euthanatized. All 6 ferrets that were submitted for necropsy had bronchopneumonia, hepatic lipidosis, mild esophagitis, and gastritis. The etiopathogenesis of megaesophagus in the ferrets was not determined.