A 15-day male neonate presented with postprandial nonbilious vomiting. Barium meal suggested pyloric obstruction. Ultrasound of the stomach after saline loading revealed an echogenic antral valve. Subsequent laparotomy confirmed the ultrasound findings. Excision of the valve resulted in excellent recovery. To our knowledge, gastric outlet obstruction because of an antral mucosal valve in a neonate has not previously been described.