In rheumatic heart disease, cardiac valves often display only a nonspecific postinflammatory scarring, without specific features, such as the rheumatic granuloma. Fifty-five native valves excised from 47 patients, exhibiting postinflammatory scarring, were studied. Patients were subdivided into three groups according to their case histories: patients with both streptococcal infection and rheumatic fever (group I), with streptococdal infection without noncardiac major manifestations of rheumatic fever (group II), and without either of these features (group III). Pathological examination alone was unable to differentiate among the three groups, all the valves showing the same general pathological features. Differences in terms of sex, age, and valvular involvement were detected among group III and the others, whereas patients belonging to the first two groups did not differ significantly. These results suggest that diagnostic criteria for rheumatic fever are too restrictive and that a postinflammatory valvular scarring of nonrheumatic etiology does exist.