The clinical and bacteriological characteristics of eight cases with purulent pericarditis observed over the last five years are studied. The route of the infection and dissemination in the majority of the cases (75 percent) was through pleuropulmonary lesions in the form of pneumonia and/or empyema, attributing the remaining cases to a subhepatic abscess and a pericardial infection after a thoracic surgical operation. In seven patients the diagnosis of the disease was established while they were alive. The more orientative clinical data were the pericardial pain (50 percent), pericardial friction murmur (25 percent), and signs of cardiac tamponade (62.5 percent). The observation of the above mentioned clinical signs together with the presence of cardiomegaly and electrocardiographic alterations suggestive of pericarditis, obliged the practice of a pericardial puncture, which confirmed the diagnosis of a purulent pericarditis by the macro and microscopic characteristics of the fluid. Staphylococcus and pneumoncoccus were isolated in two cases, respectively; other Gram-negative bacillus (E. coli and Pseudomonas aeruginosa) were isolated in the remaining cases. All patients were treated with the appropriate antibiotic according to the isolated germ; surgical drainage was carried out in six cases, and a pericardiectomy in one. Two patients died, one as a consequence of a septic myocardiopathy and the other in which the diagnosis of purulent pericarditis was not clinically suspected. During the follow-up period one case presented a constrictive pericarditis, which was corrected by a pericardiectomy.