Aim Although measurement of natriuretic peptides including N‐terminal pro‐brain natriuretic peptide (NT‐proBNP) has been recommended for identifying heart failure (HF) patients, the prevalence of elderly patients with latent HF who are attending an outpatient clinic is unknown. Methods We measured NT‐proBNP levels in 393 patients (aged 75 ± 9 years) in a rural outpatient clinic. Patients with a diagnosis of heart disease were excluded. The patients were divided into two groups by the values of NT‐proBNP: high NT‐proBNP group (>400 pg/mL) and low NT‐proBNP group (≤400 pg/mL) according to Japanese guidelines. Patients with a high NT‐proBNP value underwent echocardiography including tissue Doppler examination. Results A total of 43 (11%) patients had high NT‐proBNP values. Those patients were older, and larger percentages of those patients were male, had atrial fibrillation, history of stroke and dementia. Echocardiography was carried out in 39 of the 43 patients with high NT‐proBNP values, and there were four patients with left ventricular systolic dysfunction, two with hypertrophic cardiomyopathy and one with aortic regurgitation. In the remaining 32 patients, 27 patients had diastolic HF in accordance with Japanese guidelines. A diagnosis of HF according to the guidelines was finally made in 34 (87 %) of the 39 patients. Conclusions A large number of elderly patients without a diagnosis of HF who were attending an outpatient clinic showed high levels of NT‐proBNP, and measurement of NT‐proBNP is useful to identify patients with latent HF. Geriatr Gerontol Int 2016; ••: ••–••.