During the past ten years from 1970 to 1979, we have experienced eight cases of adrenal cortical adenoma which were diagnosed by histopathological examination in the course of the routine surgical pathology service at Department of Clinical Pathology, Catholic Medical Center in Seoul. Of the eight cases of adenoma, seven were found in the left side and one in the right side. Seven were functioning endocrinologically, while the remaining one was nonfunctioning. Of the seven functioning tumors, six were associated with Cushing's syndrome, and the remaining one Conn's syndrome. One of the patients with Cushing's syndrome manifested morphology of black adenoma of the left adrenal gland. The sex and age distribution of the cortical adenomas are summarized in Table 1, the symptoms and signs in Table 2, the endocrine findings in Table 3, and the gross and microscopic findings in Table 4.