The anti-synthetase syndrome comprises the association of an inflammatory myopathy (polymyositis, dermatomyositis), interstitial pneumonitis, skin lesions characteristic of "mechanics hands", Raynaud's phenomena, inflammatory polyarthritis and, at the biological level, antinuclear antibodies known as anti-synthetases. We report our observations of two patients, one with a typical anti-synthetase syndrome and one with an incomplete form. Two men aged 49 and 47 presented with increasing dyspnoea upon effort, muscular weakness, arthralgia, bilateral pulmonary crackles and, in the first case, typical hairless skin lesions. In both cases the chest x-rays and CT scans confirmed the presence of interstitial lesions, predominantly in the lower lobes. Lung function tests showed a restrictive pattern with reduced gas transfer. At the biological level both patients presented an inflammatory picture with elevated muscle enzymes and anti-Jo-1 antibodies. Immuno-suppressive treatment with cortico-steroids and cyclophosphamide lead to a symptomatic improvement, regression of the radiological changes and improvement in the measurements of pulmonary function.