The symptoms and findings so nicely described in the accompanying clinical report of an 8-year-old boy are those of an obstructed distal esophagus which has led to chronic mucus production, nutritional deprivation with poor weight gain, and aspiration pneumonia. It is an extraordinary clinical paradox that these signs and symptoms are exactly the same for the obstructed gastroesophageal junction, and for the wide open reflux seen with pernicious gastroesophageal reflux. Achalasia is characterized by failure of the gastroesophageal junction to relax during swallowing. The term achalasia (A-without + chalasia-relaxation), means failure of relaxation. The defect is rare in children and has been seen in very few infants.