A 1-year-old neutered male Labrador retriever was presented for investigation of chronic regurgitations that had started at weaning. Contrast radiographs and fluoroscopy of the thorax identified a focal narrowing of the proximal intrathoracic esophagus. Examination with CT-angiography excluded extraluminal causes for the narrowing, e.g., vascular ring anomaly. Esophagoscopy revealed the presence of a muscular stenosis with the appearance of a sphincter at the level of the proximal intrathoracic esophagus, without evidence of stricture. A diagnosis of congenital esophageal stenosis was made, suspected secondary to fibromuscular hypertrophy. Regurgitation resolved with conservative management and the dog was well at a 2-year follow-up examination. This case represents one of few small animal cases of congenital esophageal stenosis reported and apparently the only case successfully managed conservatively. Key clinical message: This report describes the clinical presentation, diagnostic imaging findings, and treatment of a rare case of congenital esophageal stenosis in a Labrador retriever. Medical and conservative therapies alone may be sufficient for treatment of congenital esophageal stenosis depending on presentation and suspected histopathological type. These therapies should be considered before initiating interventional procedures.