OBJECTIVE Studies comparing long-term success after pneumatic dilatation (PD) and laparoscopic Heller myotomy (HM) are lacking. This study compares long-term outcome of PD (single dilatation and graded approach) and laparoscopic HM and identifies risk factors for treatment failure. METHODS A cross-sectional follow-up evaluation of an achalasia cohort treated between 1994 and 2002 was followed-up for a mean of 3.1 years. There was a total of 106 patients treated by graded PD (1-3 dilatations with progressively larger balloons) and 73 patients treated by HM (20 had failed graded PD and crossed over to HM). A symptom assessment (structured telephone interview or clinic visit) was performed and patients were given freedom from alternative therapies to determine treatment outcome. Endoscopy, manometry, and timed barium esophagram were performed to determine the cause of treatment failure. RESULTS The success of single PD was defined as freedom from additional PDs: 62% at 6 months and 28% at 6 years (risk factors for failure: younger age, male sex, wider esophagus, and poor emptying on posttreatment timed barium esophagram). Freedom from subsequent PDs increased with each dilatation (graded PD). The success of graded PD and HM, defined as dysphagia/regurgitation less than 3 times/wk or freedom from alternative treatment, was similar: 90% vs 89% at 6 months and 44% vs 57% at 6 years (no risk factors for failure were identified). Causes of symptom recurrence were incompletely treated achalasia (96% after PD vs 64% after HM) and gastroesophageal reflux disease (4% after PD vs 36% after HM). CONCLUSIONS No treatment cures achalasia. Short- and long-term success is similar for graded PD and laparoscopic HM. Therapeutic success decreases steadily over time. Achalasia patients need careful long-term follow-up evaluation.