Seven of 23 patients (30%) seen in 2 yr with clinical and radiologic manifestations of achalasia underwent esophageal manometry demonstrating aperistalsis but apparent complete lower esophageal sphincter (LES) relaxation. Detailed clinical and laboratory evaluation suggests these patients may represent an early stage of achalasia. Duration of dysphagia and weight loss were significantly less (p less than 0.05), whereas LES pressure was similar in the 7 patients compared with the 16 more traditional achalasia patients. Isotope retention during radionuclide esophageal solid-emptying studies showed intermediate delay in emptying between normal subjects and achalasia patients. The duration of LES relaxation in this group was significantly shorter (p less than 0.01) than in normal subjects. Although complete, sphincter relaxation in these patients is functionally inadequate and may be the result of this shortened duration. The small size of standard manometry catheters may also contribute to this confusing finding. Apparent complete LES relaxation may be seen during manometry in achalasia and should not exclude its diagnosis.