Pseudallescheria boydii is a saprophytic fungus frequently isolated from agricultural soil and polluted water. Disseminated and invasive infections with this organism are seen primarily in the immunocompromised host. We present an unusual case of invasive P. boydii infection in an immunocompetent patient admitted to our hospital with clinical, laboratory and ECG findings of a possible acute myocardiac infarction. Six hours after admission without treatment with thrombolytic agents she presented with a right hemiparesis and loss of consciousness; a CT scan showed a cerebral hemorrage. She was treated with dexamethasone i.v. 32 mg per day. She was not incubated. Two blood cultures taken the 15th and 16th day of hospitalization, respectively, revealed a filamentous fungus which was identified by CBS as P. boydii. The pathologic examination of one nodule showed hyphae of fungi. Despite the administration of amphotericin B the patient died one week later.