Sixty-one pediatric and adolescent patients (age < or = 16 years) with sarcoidosis proved by biopsy specimen were identified during the period 1957 to 1976; 19 patients with elapsed time from diagnosis of 8 to 35 years (mean, 21 years) were reexamined in 1985. Age at onset of disease ranged from 4 to 16 years (mean, 12.5 years). Sex distribution was equal; 68 percent of individuals were black. At follow-up, clinical evaluation, chest roentgenograms, pulmonary function tests, electrocardiograms (ECGs), echocardiograms (ECHO), and angiotensin-converting enzyme (ACE) activity were performed on each subject. In addition, complete blood cell counts, erythrocyte sedimentation rates, serum calcium, immunoglobulin levels, B- and T-cell enumerations, and intradermal skin tests for delayed hypersensitivity were also obtained. Although all initial pediatric chest roentgenograms were abnormal, at follow-up only 37 percent were abnormal. Pulmonary function test results were available for ten children, and 90 percent were decreased. In 1985, 68 percent of the adults had abnormal lung function; furthermore, eight patients had reduced diffusing capacities, one had hypoxemia, and two had elevated ACE activity. Specific abnormalities were noted on two ECGs and 12 ECHOs. One individual had an elevated sedimentation rate, while another had an increased serum calcium level. Six patients had elevated IgA values, two had elevated IgM values, and two had depressed IgM values; IgG values were normal in all subjects. B- and T-cell percentages were unremarkable in all patients tested. Four individuals were anergic to skin test antigens. Long-term pulmonary morbidity was observed in four patients; in addition, one of these and four others suffered nonpulmonary sequelae. These results are in agreement with those of other investigators, but insufficient data still exist on the long-term effects of sarcoidosis on the pediatric host.