Pyloric stenosis, which could occur as a congenital or acquired condition, is more common in dogs when compared with other domestic animals. This condition has not been reported in Sri Lanka probably due to unfamiliarity with it and lack of diagnostic facilities. This communication discusses the clinical signs, radiographic and ultrasonographic findings, and treatment of pyloric stenosis in a one-year old female Cocker Spaniel presented to the Veterinary Teaching Hospital (VTH), Peradeniya. The patient developed projectile vomiting and distended, gas filled abdomen after meals as clinical signs. Survey radiographic findings included the 'gravel sign' in the stomach. In ultrasonography, thickened pylorus was observed. Contrast radiographs after oral administration of barium sulphate suspension showed a delay of gastric emptying. All the above findings suggested that the patient had pyloric stenosis. Complete blood count and serum biochemistry demonstrated no abnormalities. Surgical intervention was performed as treatment, using Fredet-Ramstedt pyloromyotomy together with Heineke-Mikulicz pyloroplasty to clear the obstruction in the pyloric canal. Since there were no post-surgical complications, patient was discharged in 4 days following the surgery. The prognosis was satisfactory and the animal has been healthy after the surgery. The pyloric stenosis observed in this case could be congenital, with hypertrophy and subsequent stenosis gradually worsening over time.