Fever, loss of weight, anaemia, hepatosplenomegaly and lymphadenopathy developed in two HIV-infected patients. At first malignant lymphoma with septicaemia was thought to be the cause. In both patients Salmonella enteritidis was isolated by blood culture and found to be sensitive against the antibiotics that were given (5 g azlocillin and 2 g cefotaxime, three times daily each; additionally in case 2, metronidazole, 500 mg three times daily). Because bone-marrow biopsy demonstrated acid-fast rods, antimycobacterial treatment was started (isoniazid 300 mg/d, rifampicin 600 mg/d, ethambutol 1,200 mg/d and pyrazinamide 2 g/d). Despite this the patients died of septic shock. Histological examination revealed massive amounts of acid-fast rods in spleen, liver, gut and bone marrow. Polymerase chain reaction and sequencing identified the structure as that of the recently discovered M. genavense.