Objective:To explore the therapeutic effect of peroral endoscopic myotomy (POEM) for primary achalasia (AC) in patients aged over 60 years.Methods:Data of 146 patients aged ≥60 years (the elderly group) and 146 patients aged 18-59 years (the adult group) who received POEM from November 2010 to September 2019 at the Digestive Endoscopy Center of PLA General Hospital were retrospectively analyzed. Baseline data, surgery data, surgery-related complications and surgery-related efficacy were compared.Results:There was no significant difference in gender, Ling classification, HRM classification or previous treatment between the two groups ( P>0.05). All 292 patients successfully underwent POEM surgery. The clinical success (Eckardt score ≤3) rates in the elderly group and the adult group were 96.33% (105/109) and 96.77% (90/93), respectively with no significant difference between the two groups ( χ2=0.030， P>0.05). There was no significant difference in the length of myotomy between the two groups (7.09±2.49 cm VS 7.12±2.24 cm， t=0.472， P>0.05). Complications occurred in 26 cases (17.81%) in the elderly group and 21 cases (14.38%) in the adult group with no significant difference between the two groups ( χ2=0.634， P>0.05). There was no significant difference in the postoperative hospital stay (12.61±9.69 days VS 11.00±4.43 days, t=1.825, P>0.05) or the incidence of gastroesophageal reflux [43.33% (13/30) VS 51.52% (17/33), χ2=0.422, P>0.05] between the elderly group and the adult group. Conclusion:The efficacy of POEM for AC patients over 60 years old is equivalent to that of adult patients, and the incidence of complications is similar. POEM is safe and effective for AC patients over 60 years old.