Gastro-oesophageal reflux and heartburn are reported by 45 to 85% of women during pregnancy. Typically, the heartburn of pregnancy is new onset and is precipitated by the hormonal effects of estrogen and progesterone on lower oesophageal sphincter function. In mild cases, the patient should be reassured that reflux is commonly encountered during a normal pregnancy: lifestyle and dietary modifications may be all that are required. In a pregnant woman with moderate to severe reflux symptoms, the physician must discuss with the patient the benefits versus the risks of using drug therapy. Medications used for treating gastro-oesophageal reflux are not routinely or vigorously tested in randomised, controlled trials in women who are pregnant because of ethical and medico-legal concerns. Safety data are based on animal studies, human case reports and cohort studies as offered by physicians, pharmaceutical companies and regulatory authorities. If drug therapy is required, first-line therapy should consist of nonsystemically absorbed medications, including antacids or sucralfate, which offer little, if any, risk to the fetus. Systemic therapy with histamine H2 receptor antagonists (avoiding nizatidine) or prokinetic drugs (metoclopramide, cisapride) should be reserved for patients with more severe symptoms. Proton pump inhibitors are not recommended during pregnancy except for severe intractable cases of gastrooesophageal reflux or possibly prior to anaesthesia during labour and delivery. In these rare situations, animal teratogenicity studies suggests that lansoprazole may be the best choice. Use of the least possible amount of systemic drug needed to ameliorate the patient's symptoms is clearly the best for therapy. If reflux symptoms are intractable or atypical, endoscopy can safely be performed with conscious sedation and careful monitoring the mother and fetus.