The Erasmus syndrome describes the association of generalised progressive scleroderma following exposure to silica with or without silicosis. This is a case report on four patients presenting with the Erasmus syndrome who were admitted to hospital. The analysis of the four cases enables an assessment of the cause of the dyspnoea during the course of the Erasmus syndrome. The dyspnoea presents more as scleroderma (pulmonary fibrosis in two cases, pulmonary artery hypertension in one case and localised thoracic skin disease in one case) than of pneumoconiosis. Pulmonary fibrosis should be considered where there is an association of progressive effort dyspnoea, fine crackles on auscultation and a radiological appearance either of honeycombing and/or a ground glass appearance predominantly in the posterior regions which does not exist in isolated cases of silicosis. The functional repercussion of the fibrosis is evident by a restrictive ventilatory defect which is not specific but more severe than in a case of silicosis alone. Bronchoalveolar lavage showed, in two cases of pulmonary fibrosis, an unusual polymorphonuclear neutrophilia during the course of the silicosis. The presence of ausculatory anomalies, the atypical aspects of pneumoconiosis on computed tomography and an unusual form of LBA should suggest the existence of pulmonary fibrosis associated with pneumoconiosis.