Serious infections caused by Staphylococcus aureus in HIV-infected patients have been reported. Contributing factors in the development of invasive S aureus infections include a high rate of skin and nasal colonization, frequent dermatologic disease, and the use of intravenous catheters. The authors report three cases of S aureus pericarditis in HIV-infected patients. While cases of viral, mycobacterial, and malignant pericardial effusions in HIV-infected patients have been reported, a review of the literature disclosed only three cases of bacterial pericarditis. Despite appropriate antibiotic therapy and drainage, a patient's condition may abruptly deteriorate and progress to tamponade. Early recognition of bacteremia and pericarditis and monitoring for cardiac tamponade, along with aggressive treatment, can result in a favorable outcome, but mortality remains high, particularly when S aureus is the causative agent.