A 47-year-old male was diagnosed as having idiopathic achalasia on the basis of clinical, roentgenographic, and manometric criteria. He was on no medication and had no disorders known to impair esophageal motility. He was treated by pneumatic dilation with a good clinical response. On reexamination 7 years later, several features considered to be typical of achalasia were no longer present. Changes included return of peristaltic activity throughout most of the body of the esophagus, failure of a direct-acting cholinergic agent to produce an increase in base line intraesophageal pressure, and failure of a direct-acting cholinergic agent to produce a heightened response at the lower esophageal sphincter (LES). Incomplete LES relaxation in response to swallowing persisted. This represents the first reported case of return of esophageal peristalsis in idiopathic achalasia.