The antiphospholipid syndrome is defined by the association of vein and/or arterial thrombotic events and a high level of antiphospholipid antibodies. Pulmonary embolism and pulmonary hypertension are the most usual complications and recently some new cases of alveolar haemorrhage have been described. We present the case of an alveolar haemorrhage in a patient with a primary antiphospholipid syndrome. The first manifestation of this patient was a deep vein thrombosis on his left lower leg . After that he had persistent hemoptoic sputum and his chest x-ray showed alveolar infiltrates. The bronchoscopy ruled out another causes of haemoptysis and the bronchoalveolar lavage confirmed that it was an alveolar haemorrhage (80% of hemosiderophages ). The case is discussed and we do a literature review.