Since the discovery of Helicobacter pylori (H. pylori) infection in the stomach, the bacteria infection and non-steroidal anti-inflammatory drugs (NSAIDs) use had been considered to be the 2 main causes of peptic ulcers. However, there have been recent reports of an increase in the proportion of peptic ulcers without these known risk factors; these are termed idiopathic peptic ulcers. Such trend was firstly indicated in 1990s from some reports in North America. In Asia, numerous studies reported that idiopathic ulcers accounted for a small percentage of all ulcers in the 1990s, but in the 2000s, multiple studies reported that the proportion of idiopathic ulcers had reached 10%-30%, indicating that the incidence of idiopathic ulcers in Asia has also been rising in recent years. While a decline in H. pylori infection rates of general population in Asia is seen as the main reason for the increased incidence of idiopathic ulcers, it is also possible that the absolute number of idiopathic ulcer cases has increased. Advanced age, serious systemic complication, and psychological stress are considered to be the potential risk factors for idiopathic ulcers. Management of idiopathic ulcers is challenging, at present, because there is no effective preventative measure against recurrence in contrast with cases of H. pylori-positive ulcers and NSAIDs-induced ulcers. As it is expected that H. pylori infection rates in Asia will decline further in the future, measures to treat idiopathic ulcers will also likely become more important.