Achalasia is a primary esophageal motor disorder characterized by lack of esophageal peristalsis and poor lower esophageal sphincter (LES) relaxation. Clinically, achalasia manifests as progressive dysphagia to solids and liquids and mild weight loss. Predisposition to esophageal cancer is not prevalent, but certain tumors may mimic achalasia. The diagnosis of achalasia is relatively easy to make with a good history, radiography, and esophageal motility testing. The esophagogram reveals a typical bird-beak narrowing of the esophagogastric junction and esophageal dilation, the degree of which depends on the stage of the disease. Esophageal manometry reveals poor LES relaxation, aperistalsis, and often elevated intraesophageal pressure. Endoscopic examination is important to rule out malignancy as the cause of achalasia. The traditional treatment of achalasia is forceful dilation of the LES. Bougienage may be helpful in some cases. Pharmacological agents, such as nitroglycerin and calcium channel blockers, provide some relief by decreasing LES pressure. However, they are not a viable, long-term choice. Surgical myotomy offers slightly better results than pneumatic dilation, but it is accompanied by some increased gastroesophageal reflux. Laparoscopic and thoroscopic myotomy are in their infancy, and, if successful, they will make surgical treatment much more attractive. Intrasphincteric botulinum toxin injection is the newest form of therapy. Its safety and ease of administration are very encouraging, but long-term results are not available.