Esophageal achalasia is the most frequent primary motor disorder of the esophagus, resulting in a peristalsis and failed relaxation of the lower esophageal sphincter (LES). Various treatments have been described. Endoscopic alternatives include botulinum toxin injection and pneumatic balloon dilation, but both tend to fail with time and usually repeated interventions are required. Laparoscopic Heller myotomy (LHM) has been considered the gold standard. The diagnosis of achalasia during pregnancy is extremely rare and optimal management remains unclear. Our aim was to report a successful per oral endoscopic myotomy (POEM) performed during pregnancy. A 40-year-old pregnant woman presented with esophageal achalasia during her first trimester. Her disease was diagnosed with high resolution esophageal manometry (HREM). Initially an expectant conduct was attempted, but dysphagia progressed during the first 6 weeks of follow-up and an important weight loss was noticed. She underwent POEM at 15 weeks of gestation. After the procedure, she reported relief of both dysphagia and regurgitation, and her nutritional status improved. She delivered a healthy boy at term. During follow-up, she remains without dysphagia, her upper GI endoscopy shows no esophagitis and her HREM reports a normal integrated relaxation pressure. In achalasia, as in other clinical conditions, therapeutic decisions during pregnancy should always consider both the welfare of the mother and the fetus. POEM is a purely endoscopic treatment and has been recognized as a safe procedure to treat achalasia, with postoperative clinical success comparable to LHM and potential benefits over it.