One of the potential consequences of carrying out a Heller's myotomy for achalasia is gastro-oesophageal reflux. Whether it is frequent or severe enough to warrant the routine addition of a fundoplication to the operation is debated. In this prospective series of all patients undergoing a myotomy using a minimally invasive method the incidence of gastro-oesophageal reflux disease is examined. It was found that in 124 patients who had been followed for at least 6 months, whereas mild heartburn was common (51 patients; 41%), in only 10 patients (8.2%) was a proton pump inhibitor required and there were no patients whose reflux was not controlled using standard medical treatment. Peptic oesophagitis was an infrequent endoscopic finding with only 3 of 40 patients with no or mild heartburn having mild oesophagitis and no patient on a proton pump inhibitor having active peptic oesophagitis. These findings suggest that the addition of a fundoplication to a Heller's myotomy to prevent gastro-oesophageal reflux disease is not essential.