Nailfold capillary abnormalities in 40 patients suffering from progressive systemic sclerosis (scleroderma; PSS) were studied by widefield nailfold capillary microscopy. Capillary enlargement and loss were graded using the rating scales of Maricq and Minkin. Capillary changes were correlated with organ involvement and immunological abnormalities. A high correlation was found between the grade of nailfold capillary changes and the clinical severity of PSS. Nailfold capillary microscopy seems to be a useful method to get quick information in order to predict organ involvement in PSS.