Phonocardiographic recordings were obtained in 39 elderly patients (ages 49–82 years) in order to detect the presence or absence of a fourth heart sound (S<sub>4</sub>). The group included 20 patients with no known cardiac disease and 19 with overt clinical heart disease. Each subject was also examined clinically by two independent observers. An S<sub>4</sub> was heard in 5 patients of the normal group by one clinician and in 9 by the other. In patients with heart disease, an S<sub>4</sub> was heard in 8 cases by the first clinician and in 11 by the second one. An S<sub>4</sub> was recorded in 11 of the 39 patients, including 4 of 20 normals and 7 of 19 with heart disease. None of the differences between groupswas statistically significant. It is concluded that in elderly subjects, an S<sub>4</sub> may occurin the absence of overt heart disease.