Among 195 patients with pulmonary embolism admitted to our hospital, three men and three women, 16 to 65 years old, developed a pericardial syndrome five to 15 days after the onset of pulmonary embolism and infarction. Other known causes of pericarditis were ruled out by clinical history and ancillary methods. The six patients had a pericardial rub, fever, anemia, leukocytosis, and increasing sedimentation rate; four had a pericardial effusion; two had a pleural effusion. One patient, with coexisting heart disease, died after another episode of pulmonary embolism; in the other five, oral corticosteroids induced complete remission of the pericardial syndrome. This type of pericarditis deserves wider recognition.