Neonatal pneumopericardium is a rare clinical condition which usually occurs in association with other air leaks, especially when there is severe lung pathology, post vigorous resuscitation, or in presence of assisted ventilation. We report the first case of isolated, spontaneous pneumopericardium occurring in the absence of a history of neonatal resuscitation, mechanical ventilation, or of significant lung pathology. In this neonate the pneumopericardium had a relatively benign course resolving on oxygen therapy. We also review the literature and highlight the differences between the early onset, often spontaneously resolving cases, and the late onset usually severe cases.