Introduction : Achalasia is a well defined esophageal motor disorder. Available therapeutic options include surgical myotomy, pneumatic dilation, and more recently intrasphincter botulinum injection. Aim: To compare the efficacy of botulinum toxin injection and pneumatic dilatation in the treatment of achalasia. Methods : Thirty-nine consenting symptomatic adults newly diagnosed with achalasia were consecutively enrolled.The diagnosis was established based on clinical, radiologic, endoscopic and manometric criteria. Exclusion criteria included age less than forty, pregnancy, coagulopathy, serious medical illness or malignancy. Patients were randomized to receive either botulinu toxin injection (20 pats.) or pneumatic dilatation (19 pats.).Over a duration of 12 months, efficacy was assessed on the basis of an esophageal symptom score. Symptom scores were evaluated at 1,6 and 12 months. Clinical recurrence was defined as an increase of sympyom score to greater than 50% of baseline. If symptoms recurred, retreatment was administered with a second botulinum toxin injection or a second pneumatic dilatation. Clinical response to retreatment was followed for the remained of 1 year. If symptoms recurred after retreatment the patient was considered a treatment failure. The 1 year incidence of retreatment and treatment failure was estimated by the Kaplan-meier method. Results : The cumulative retreatment rate (relapse after 1 treatment session) was significantly higher in the botulinum toxin group than the pneumatic dilatation group (P Conclusion : Treatment of achalasia with pneumatic dilation is more efficacious than botulinum toxin in providing sustained symptomatic relief over a one-year duration. The efficacy of a single pneumatic dilation is similar to that of two botulinum toxin injection.