Introduction: Achalasia is a most frequent primary motility disorder of the oesophagus with the prevalence of 10/100,000 individuals, with no gender predominance. Due to its rare occurrence, at the early stages may be erroneously diagnosed, leading to progression of disease and delayed treatment. Objectives: The main aim of the review is to depict current data about achalasia, including pathogenesis, diagnosis, and possible treatment modalities, particularly the latest, minimally invasive technique: per-oral endoscopic myotomy (POEM). State of knowledge.: The ethology of achalasia remains unknown, although autoimmune, viral or neurodegenerative causes may be considered triggers of the disease. In some cases, achalasia may be secondary to other conditions (e.g. malignancy, Chagas disease). Typical symptoms of achalasia are dysphagia (for both liquids and solids), regurgitations, heartburn and mweight loss. The diagnosis is based on endoscopy, oesophageal high-resolution manometry (HRM) and X-ray with barium swallow. Therapies used in the treatment of achalasia focus on improving food passage by reducing LES pressure. These procedures include pharmacologic treatment, pneumatic balloon dilation, Heller myotomy and endoscopic myotomy. POEM was first introduced in humans by Inoue in 2008. Recent studies have revealed excellent short-term outcome of POEM with no serious complications Conclusions: Achalasia is an incurable disease; however, available therapies can effectively reduce patients` symptoms. Further evaluation may lead to the establishment of tailored-to- patient treatment, and it is believed that POEM will become a gold standard for treatment of achalasia.