Helicobacter pylori (H. pylori) is the most common cause of peptic ulcers, and is considered as carcinogenic with respect to gastric cancer and MALT lymphoma. The role of H. pylori in other gastroduodenal diseases like atrophic gastritis and functional dyspepsia has been investigated in hundreds of works, but little is done about what role H. pylori may play in non gastric diseases. Gastro-esophageal reflux disease does not seem to be related to H. pylori but Barrett's esophagus might be. Inflammatory bowel diseases tend to be reverse correlated with H. pylori. In coronary heart disease some studies have shown a connection, others not. Diabetes is not likely to be H. pylori-associated and nor do liver diseases with exception for cirrhosis, where a correlation is possible. Respiratory diseases are little examined but bronchiectasis might have a correlation with H. pylori. A small series of children, who had died in sudden infant death, showed a high rate of H. pylori infection.