A 13-year-old male intact Golden Retriever was presented for chronic regurgitation and vomitus. The only clinical abnormality was halitosis, a neurological examination was normal. Thoracic radiography revealed a moderately distended, air-filled esophagus and a presumptive diagnosis of idiopathic megaesophagus was made. No other disorder causing abnormal esophageal motor function could be identified. As supportive and anticholinergic therapy failed to improve the dogs condition and ongoing regurgitation worsened, owners opted for euthanasia. Postmortem examination revealed a small (1.5 cm diameter) mass in the terminal esophagus. Microscopically a leio-myoma with mild multifocal mixed-cell esophagitis was diagnosed. This report illustrates how a potentially curable disease such as leiomyoma can clinically mimic acquired idiopathic megaesophagus and emphasizes that additional diagnostic procedures (contrast study, esophagoscopy) can be indicated in individual cases.