ObjectiveTo compare the curative effects of water-filled balloon dilatation and botulinum toxin local injection in treatment of achalasia by evaluating the clinical symptoms and esophageal kinematics. MethodsEighty patients diagnosed as primary achalasia were randomly assigned to endoscopic water-filled balloon dilatation group and botulinum toxin group in a prospective randomized controlled trial. The clinical symptoms and esophageal kinematics of patients were evaluated before and 1 week, 1 month after therapy, and the data of remission were recorded during a follow-up of 24 months. ResultsThe clinical symptom scores (overall symptom, regurgitation of food, dysphagia and chest pain) and esophageal kinematics (the lower esophageal sphincter resting pressure and relaxation rate of lower esophageal sphincter, contracting amplitude of esophageal body and the percentage of esophageal body antegrade peristalsis) were significantly improved in both treatment groups 1 week and 1 month after therapy (P<0.01) . One week after treatment the improvements in regurgitation and dysphagia scores were greater in water-filled balloon group than those in the botulinum toxin group (P<0.05, P<0.01). The reduction in lower esophageal sphincter resting pressure was greater in water-filled balloon group than that in the botulinum toxin group 1 week and 1 month after treatment (P<0.01). After 12 months, the clinical remission rates in water-filled balloon group and botulinum toxin group were 73.2% and 61.5%, respectively; Kaplan-Meier analysis demonstrated no significant difference in the accumulated remission rates between the 2 groups(P=0.29). ConclusionBoth endoscopic water-filled balloon dilatation under endoscope and botulinum toxin local injection are effective for treatment of achalasia, with better therapeutic effect seen for water-filled balloon dilatation.