Background/Aims: Per-oral endoscopic myotomy (POEM) is an established treatment for achalasia. The technique of POEM is still evolving and the impact of length of esophageal myotomy on the outcomes of POEM is not known. In this study, we aim to compare the outcomes of short (3 cm) versus long (6 cm and above) esophageal myotomy in patients undergoing POEM for achalasia cardia. Methods: Consecutive patients with idiopathic achalasia (type I and II) were randomized to receive short (3 cm) or long esophageal myotomy (≥ 6 cm).Both groups were compared for clinical success, operative time, adverse events, and gastroesophageal reflux disease (GERD). Results: Seventy-one consecutive patients with type I and II achalasia underwent POEM with short (n = 34) or long (n = 37) esophageal myotomy techniques. Mean length of esophageal myotomy in short and long groups was 2.76 ± 0.41 and 7.97 ± 2.40, respectively (P < 0.001). Mean operative time was significantly shorter in short myotomy group (44.03 ± 13.78 minutes and 72.43 ± 27.28 minutes, P < 0.001). Clinical success was comparable in both arms at 1-year (Eckardt score 0.935 ± 0.929 vs 0.818 ± 0.983, P = 0.627).Improvement in objective parameters including integrated relaxation pressure and barium column height at 5 minutes was similar in both groups. GERD was detected in 50.88% patients with no significant difference in short and long myotomy groups (44.44% vs 56.67%, P = 0.431). Conclusions A short esophageal myotomy is non-inferior to long myotomy with regards to clinical success, adverse events, and GERD in cases with type I and II achalasia. Reduced operating duration favors short esophageal myotomy in these patients.