The purpose of this study was to describe the etiologies and outcomes of pericarditis in children. Methods: Records of cases diagnosed with pericarditis or pericardial effusion from 1972-1997 were reviewed. Postoperative effusions were excluded. Results: Ninety-seven cases were reviewed. Nineteen (19.6%) were bacterial, 5 Haemophilus influenza B. No cases of Haemophilus influenza B were seen since the advent of immunization for this organism in 1990. After 1990 bacterial pericarditis has included 2 cases that were culture negative and one case of each of the following; methicillin resistant S. aureus, M. tuberculosis, and Haemophilus influenza F. The overall age of the pts with bacterial pericarditis (3.7 ± 6.2 yr±SD) was younger than the pts with other etiologies (8.4 ± 6.7 yr±SD) (p<0.01). Twenty-six (26.8%) were viral or idiopathic. Twenty-one (22.1%) were associated with connective tissue or immunologic disorders. Nine cases (9.3%) were related to malignancy. Miscellaneous inflammatory disorders accounted for 4 cases and 18 were attributable to other non-inflammatory etiologies. Twelve cases had pericardial window performed and 10 had pericardiectomy. Three of these patients with surgical treatment required repeat intervention. No deaths were seen due to pericarditis or pericardial effusion. There have been no recognized cases of late pericardial constriction. Conclusion: 1) Bacterial pericarditis accounts for about 1/5 of cases of pericarditis in childhood. 2) The children with bacterial pericarditis are younger than other etiologies as a group. 3) Haemophilus influenza B has become uncommon since immunization for this organism has begun. 4) Mortality and late morbidity from pericarditis is rare.