Objective: to describe the clinical characteristics and lower esophageal sphincter (LES) pressures on highresolution manometry (HRM) in patients with achalasia pre- and post-treatment. Methods: a case series study was conducted in achalasia patients. Clinical symptoms, Eckardt score, upper gastrointestinal endoscopy, esophageal barium swallow, and HRM results were collected on baseline and Eckardt score and HRM results on follow-up were collected. Results: from June 2018 to December 2019, 14 patients were recruited including 6 males and 8 females with mean age of 34.6±10.5 y. The proportion of achalasia type I, II, and III were 28.6, 64.3, and 7.1%, respectively. The Eckardt score, LES resting pressure (for both baseline period and swallow phase) and 4-s integrated resting pressure (IRP4s) significantly decreased after treatment (p