Systemic lupus erythematosus (SLE) is a chronic autoimmune disease, which generally affects young females. Its familial form is rarely reported. We describe a case of an exudative ascites revealing familial and late onset SLE. A 62-year-old patient with a history of pericarditis and a right heart failure complicating Pulmonary arterial hypertension (PAH) at 100 mmHg, presented with dyspnea. The patient has a 27-year-old daughter followed up SLE with shrinking lungs. The examination revealed polypnea, signs of right heart failure and an important ascites without collateral venous circulation or fever. The Examination of the ascitic fluid revealed exudative-type ascites with 42g/L of protein, 1030 of white elements 65% lymphocytes and 35% neutrophils; but no malignant cells. Cultures for bacteria and mycobacteria gave no growth with a negative PCR for tuberculosis. The patient had lymphopenia, thrombocytopenia and a direct coombs test positive for IgG 2 ++ with a proteinuria 1.04 g/24 h. Immunological examination showed the presence of  the anti-nuclear antibodies at a homogeneous titer of 1/3200 with the presence of native anti-DNA (1/800), anti-nucleosome, anti-ribosome, anti SSA and anti -histone. The diagnosis of  SLE was established and she had bolus of methylprednisolone   1g / day for 3 days then relayed by prednisone 1mg / kg / day associated to  hydroxychloroquine, Sildenafil and a calcium channel blocker for her PAH. The evolution was marked by the improvement of her respiratory state and her polyseritis. Exudative ascites are rarely reported. This is a rare case of an exudative ascites revealing familial and late onset SLE associated to Sjögren’s Syndrome.