Helicobacter pylori (H. pylori) is involved in the development of several gastroduodenal diseases. Since the latest decade, several studies have reported on the link between chronic H. pylori infection and a variety of extragastric manifestations, including dementia. To identify the publications on the association between H. pylori and dementia, a MEDLINE search was conducted. Although case-control studies reported controversial data, a recent longitudinal population-based cohort study found that after 20 years of follow-up, 28.9% of H. pylori-positive versus 21.1% of H. pylori-negative subjects developed dementia. After correction for confounding factors, the infection was significantly associated with higher risk of developing dementia (P=0.04). Moreover, in another study evaluating the effect of H. pylori eradication on the progression of dementia in Alzheimer's disease patients with peptic ulcer, the cure of the bacterium was associated with a decreased risk of dementia progression compared to persistent infection. To date, defining H. pylori as a target for prevention or treatment of dementia remains a topic with much controversy but of essence, as any relationship would reduce, due to the cost-effectiveness of the therapy, a burden on the National Health Care budget. The need for extensive studies with appropriate epidemiological and clinical approaches is crucial to investigate a potential causal relationship.