Two hundred twenty two auricular appendages from patients with acquired and congenital heart diseases, that were obtained through valvoplasty procedures during a period of 10 years from 1967 to 1976, were examined histopathologically at the Department of Pathology, College of Medicine, Seoul National University. Among 80 cases of acquired heart disease (mitral stenosis 66 cases; mitral stenoisufficiency 7 cases: mitral insufficiency 5 cases; mitral stenosis and tricuspid insufficiency 2 cases), there were 12 cases (15%) of endocardial granulomas, 5 cases (6.2%) of myocardial granulomas, 6 cases (7.5%) of endocardial basophilic degeneration and 8 cases (10%) of myocardial basophilic degeneration. Cellular infiltrations of endocardium were observed in 8 cases (10%) and of myocardium in 14 cases (18%). Endocardial fibrosis was seen in 22 cases (18%) and myocardial fibrosis in 5 cases (6.2%), respectively. Myocardial hypertrophy was found in 77 cases (96.3%), in which 24 cases (30%) of mild degree, 31 cases (38.8%) of moderate degree and 22 cases (17.5%) of severe degree were included. Incidence and severity of the above lesions from patients with acquired heart disease were relatively low comparing with those of other authors. Incidence of auricular lesions of the congenital heart disease was very low. Authors also observed various gradational changes of vascular sclerosis of lung biopsy specimens that were obtained at the time of surgery together with the auricular appendage. These findings suggest that the severity of vascular sclerosisis is in parallel to the severity of myocardial hypertrophy as well as to the duration of the illness.