An ultrastructural study was made on the nailfold capillaries in an 18-year-old female with eosinophilic fasciitis. Scleroderma-like capillaroscopic lesions were visible at the sites where biopsy was performed. Light microscopy revealed ectasic capillaries at the apex of dermal papillae. Aspects of thickening and duplication of the epidermal basement membrane as well as an activation of endothelial cells were visualized at the ultrastructural level. These cells contained many virus-like tubulo-reticular inclusions, associated with cisternae of endoplasmic reticulum. Aspects of degeneration of nerve fibres and Schwann cells were also present. Large, homogeneously electron-dense deposits could be seen in the basement membrane at the dermo-epidermal junction. This study not only confirms previous observations on the microangiopathy in eosinophilic fasciitis, but also documents two new aspects: electron-dense deposits at the dermo-epidermal junction and tubulo-reticular inclusions within endothelial cells.