We compared the clinical, radiographic, and manometric findings in 10 patients with atypical achalasia showing complete lower esophageal sphincter (LES) relaxation to 39 patients with classic achalasia (i.e., incomplete LES relaxation). Those with atypical achalasia were younger (46.1 vs 60.6 years), had dysphagia of shorter duration (18.7 vs 45.7 mos), had lost less weight (8.2 vs 21.5 lbs), and had less esophageal dilatation (2.8 vs 3.9 cm). However, the mean LES pressures (34.5 vs 37.7 mmHg) and the esophagogastric junction calibers (4.5 vs 4.8 mm) were similar. Radionuclide esophageal emptying studies were done in 15 patients (6 with atypical achalasia; 9 with classic achalasia) and were abnormal in all. Most patients in both groups (90 and 92%) responded well to pneumatic dilatation. We conclude that achalasia with apparent LES relaxation may represent an early form of this motor disorder and that the radiographic findings remain characteristic except for less dilatation of the esophagus.