Introduction: idiopathic pulmonary hemosiderosis is a rare disease of unknown etiology. Case report: This is a 12-year-old boy. The beginning of its symptomatology dates back to one year by several episodes of low-abundance hemoptysis associated with cough and night sweats. He had also a microcytic hypochromic anemia (Hb=4.4) transfused 3 times. . Clinical examination found discoloured skin paleness and conjunctival The count showed microcytic hypochromic anemia with HB:5.7 g/dl. A chest x-ray showed a discrete alveolar syndrome. A tuberculous assessment in particular an IDR tuberculin 3 BK expectorations and Gènexpert were negative. A chest CT scan showed bilateral interstitial syndrome. A bronchoscopy with bronchoalveolar lavage showed the existence of sidephages with a Golde score calculated on 240 Perls staining . A balance of system diseases including antinuclear antibodies were negative. Ac anti transglutaminase IgA were negative. A heart ultrasound did not show a pulmonary hypertension. In fine, the diagnosis was a primary pulmonary hemosidesis. Management consisted of a blood cell transfusion a prenisolone-based corticosteroid 2 mg/kg/d for 3 months. After two months, the improvement was full. Conclusion: We must think about Hemosidesis idiopathic if we have hemoptysis chronic anemia and pulmonary infiltrates and do a Bronchoalveolar lavage to confirm diagnosis.