We report immediate and late clinical results achieved in 33 patients with achalasia treated with pneumatic dilation as an outpatient procedure. Thirty patients were seen before any therapy and 3 following a failed esophagomyotomy. All patients were submitted to clinical, radiological and manometric evaluation before treatment: six of them belonged to Adams' class I, 19 to class II and 8 to class III. The dilations were performed with Microvasive Regiflex System (30-35-40. mm.). The average number of dilations per patient was 1.4; one dilation was performed in 25 patients, 2 dilations in 6, and three dilation in two. The patients after the dilation were controlled for a maximum period of 3 hours before being discharged from the outpatient facilities. No complications, worthy of note, was related to the procedures. The clinical results were subdivided in four classes according to Vantrappen's schema. Ten days--immediate results--after the first dilation excellent-good results were obtained in 26 patients (78.8%); moderate results in four (12.1%) and poor results in three (9.1%). The mean LES pressure, evaluated in 15 out of 25 cases fell from 37.6 mmHg. Before treatment to a value of 16.2 mmHg after treatment (p < 0.005). Of the 30 patients followed for an average period of 30.6 months (2-82)--late results--excellent-good results were obtained in 24 (80%), moderate results in 4 (13.3%) and poor in 2 (6.7%). In conclusion the clinical results, of our study, repeat those published in a previous prospective evaluation.(ABSTRACT TRUNCATED AT 250 WORDS)