A 60-year-old male patient with a Björk-Shilley type mitral metal prosthesis and tricuspid annuloplasty 20 years earlier due to rheumatic valve disease, chronic atrial fibrillation (CAF), AHT, congestive heart failure (CHF) with a NYHA Functional Grade I/IV. He was receiving treatment with acenocoumarol. He was admitted to our department due to fever, chills, and worsening of his usual dyspnoea, with the appearance of orthopnoea and oedema in the lower limbs. The clinical examination was compatible with CHF (jugular veins ingurgitated, arrhythmic pulse at 100 bpm, gallop rhythm, bilateral basal pulmonary crackles, hepatomegaly of 2 crossings with positive hepatojugular reflex and pretibial oedema with fovea in MMII). Blood tests showed haemoglobin 12.4 g/L, leukocytes 17,810/ml, with 87% neutrophils, the rest of the usual parameters being within the normal range. Chest X-ray showed signs of CHF. Serial blood cultures were performed in which Neisseria Sicca was persistently isolated, so treatment was started with intravenous Penicillin G sodium 24 million units in continuous perfusion and Gentamicin 80 mg I.V. every 8 hours (first 2 weeks), and the patient was afebrile on the third day of starting treatment. During admission, reddish, painful lesions appeared on the fingertips of both hands compatible with vasculitic phenomena, and a diagnosis of Infective Endocarditis (IE) was made according to Durack's clinical criteria (4). Transthoracic Echocardiography (TTE) and Transesophageal Echocardiography (TEE) showed a normofunctioning mitral prosthesis and absence of vegetations. On the 9th day of treatment, the patient presented an abrupt episode of loss of strength in the left hemibody, and a cranial CT scan showed 3 hyperdense images at the temporal-parietal and occipital levels of both hemispheres compatible with haemorrhagic foci. At that time, the NRI was 2.45, in spite of which anticoagulation was suspended. Four days later, and after stabilisation of the patient, it was decided to restart anticoagulation with iv sodium heparin, completing 6 weeks of antibiotic treatment and heparin. In the follow-up CT scan of the brain after treatment, the occipitoparietal haematoma persisted, the other haemorrhagic foci having disappeared. Given these findings and the possibility of rebleeding, the patient was discharged with bemiparin 10,000 I.U. subcutaneously once a day for 3 months, after which a new echocardiographic study and cranial CT scan were performed, which showed the normality of the mitral valve and the practical resolution of the cerebral haematoma, for which reason oral anticoagulation with acenocoumarol was started again, and three months later he was found to be asymptomatic.