Achalasia is a rare oesophageal motility disorder predominantly causing dysphagia and regurgitation of food and fluids. Diagnosis is made typically after a combination of tests including endoscopy, barium swallow and oesophageal manometry. The advent of high-resolution manometry has led to the Chicago Classification which divided achalasia into three types. This improved the understanding of presentation, prognosis and might also help tailor therapy. Botulinum toxin has been shown to have good, but short-term efficacy. The predominant treatments include pneumatic balloon dilatation and laparoscopic Heller's myotomy, both of which have similar and durable outcomes, although the success of both reduces with time. Per-oral endoscopic myotomy (POEM) has been shown to be as effective, safe and durable as earlier treatments for achalasia; however, randomised controlled trials are lacking. Indications for POEM are expanding to other hypercontractile motility disorders of the oesophagus.