A case of a paraventricular brain abscess, which favourably responded to conservative intensive therapy, is reported. A central venous catheter was the cause of myocardial necrosis leading to cardiac tamponade. In an attempt to tap the effusion, the partly necrotic cardiac wall was perforated. Only by recognition of the danger, by intensive clinical observation of a patient and by regular checkup of the catheter tip were the fatal complications following central venous catheterization avoided.