SUMMARY During the last 13 years 264 unselected patients with achalasia have been treated solely by the technique of pneumatic dilatation. The principle of the method was to continue the series of consecutive dilatations until the result was satisfactory. This paper reports the late results in 138 patients who were treated more than three years ago (3-13 years; mean 6.6 years). The results were evaluated by somebody who had not before been involved in the treatment of achalasia. The evaluation was based on a personal interview, a standardized radiological examination, and intraluminal pressure measurements.These late results were classified as excellent in 45 %, good in 32%, moderate in 17%, and poor in 6 %. The best results were obtained in patients with a history of five to twenty years and a moderately dilated oesophagus (50-80 mm.). Comparison of the clinical results with the manometric data obtained before, immediately after, and late after treatment indicates that intraluminal pressure measurements may be a useful guide for the treatment of achalasia by pneumatic dilatations.