BACKGROUND: Purulent pericarditis is an unusual first manifestation of HIV-infected patients. Co-infections in this scenario are possible and challenging. Mycobacterium tuberculosis is a frequent agent in purulent pericarditis related to HIV infection but co-infection with Staphylococcus aureus is rarely reported.

CASE PRESENTATION: We describe a rare case in otherwise asymptomatic 39-year-old diabetic man with acute purulent pericarditis leading to tamponade due to S. aureus and evidences of M. tuberculosis co-infection. Testing for human immunodeficiency virus was positive.

CONCLUSION: Primary purulent pericarditis is a rare condition and may indicate underlying HIV infection. In this scenario, coinfection with multiple organisms are possible and patient should be tested for underlying tuberculosis in addition to standard microbiological workup.