BACKGROUND Memory disorders and Alzheimer's disease (AD) share the same risk factors with cardiovascular diseases. OBJECTIVE We tested whether elevated N-terminal pro-brain natriuretic peptide (NT-proBNP) levels would predict any incident dementia or AD. METHODS The association between NT-proBNP and the risk of dementia was evaluated in a total of 7,158 subjects without previous memory disorders in a prospective study with a median follow-up of 13.8 years. RESULTS A total of 220 new dementia cases occurred, of which 149 were AD. Baseline logNT-proBNP levels were associated significantly with the risk of dementia in the entire study population (HR 1.32, 95%CI 1.17-1.56, p = 0.001) per 1SD difference, adjusted for multiple cardiovascular risk factors. Integrated discrimination improvement (IDI) and continuous net-reclassification improvement (continuous NRI) were improved in the study population over 40 years of age: continuous NRI was 17.5% (95%CI 4.4-30.6%, p = 0.009) and IDI was 0.005 (95%CI 0.001-0.010, p = 0.021). Regarding AD, the HR for 1SD logNT-proBNP change was 1.23 (95%CI 1.01-1.49, p = 0.040) in the entire study population, but no IDI or continuous NRI improvement was seen. CONCLUSION NT-proBNP is also an independent risk marker for dementia, and patient discrimination regarding dementia risk could be improved by using it.