Sarcoidosis is a multisystem disorder of unknown aetiology characterized by immune granuloma in involved tissue with predilection for lung and lymphoid system. The sarcoidosis aetiology remains unknown. It could result of genetic predisposition and exposure to specific enviromental factors. The chest X-ray is abnormal in 90% of cases with adenopathies and/or massive pulmonary infiltration with or without fibrosis. The different aspects are classified in 4 stages. The diagnosis is done when clinical and radiological usual signs are present with histological granuloma without caseum and in the absence of any other granulomatous disease. Most of the time, sarcoidosis spontaneously heals in 2 to 3 years. 10 to 30% of cases are chronic and often more severe. The disease could lastly generate a pulmonary fibrosis with a potential respiratory insufficiency, cor pulmonale, or aspergillus infection. Cardiac, neurologic, throat, kidney or ophthalmologic lesions or hypercalcemia may also be of bad prognosis. Sarcoidosis is lethal in 0.5 to 5% of cases. Mild disease does not need to be treated. Systemic corticosteroid for 12 months at least is the treatment for more severe diseases. Antimalarials drugs and immunomodulatory agents may be used if corticosteroids cannot be used or failed. TNFalpha recently proposed is currently evaluated.