Systemic sclerosis is a generalised connective tissue disorder characterised clinically by thickening and fibrosis of the skin and by the involvement of such internal organs as the kidneys, lungs, heart and gastro-intestinal tract. Although the aetiology of systemic sclerosis is unknown, its prevalence has been reported to be increased in workers exposed to silica. Most pathogenic findings in patients with systemic sclerosis involve changes in the vascular system, immunological anomalies and disturbances in the regulation of fibroblast function. Two subsets are recognised according to the degree of skin involvement: the limited cutaneous form, usually confined to acral features; and diffuse cutaneous scleroderma, manifesting involvement both of the trunk and extremities. The latter subset is characterised by more rapid progression of skin and visceral involvement, poorer prognosis and manifestly reduced survival. No adequate therapy has been found, and optimal use of the available therapies necessitates accurate subset assignment of the patient in order to be able to assess the stage of disease in relation to vascular, immunological and fibroblast function changes.