The anti-synthetase syndrome is associated with inflammatory myopathy, interstitial lung disease, polyarthritis, Raynaud's phenomenon and typical skin lesions known as "mechanic's hands". Anti-Jo1 antibodies are frequently present. Interstitial lung disease is the most important feature, as it determines survival and the therapeutic attitude. We report here two cases of anti-synthetase syndrome with acute respiratory failure. Immunosuppressive treatment combining corticosteroids and cyclosporine lead to clinical improvement, regression of radiological lesions and improvement in pulmonary functions.