We describe a case of active systemic lupus erythematosus (SLE) complicated with a large amount of pericardial effusion with diastolic collapse of right ventricle suggestive of tamponade. Isolates from surgical drainage of pericardial fluid showed Acinetobacter baumannii exhibiting multiple antibiotics resistance. Despite the high frequency of both pericardial involvement and of infection complications in SLE, septic pericarditis and tamponade is considered rare. Most of the reported cases of septic pericarditis in SLE were due to Staphylococcal aureus, and Acinetobacter baumannii has never been reported before.