The association between systemic lupus erythematosus and antiphospholipid syndrome can cause several complications. We report a 45 years old woman, treated with steroids for a systemic lupus erythematosus. She presented with a clinical picture of a lupus pneumonitis and, subsequently, with the picture of a pulmonary thromboembolism. The diagnosis was confirmed by helicoidal computed axial tomography. The patient was treated with anticoagulants, with a favourable outcome.