Three sisters with adult fucosidosis showed prominent psychomotor retardation, gargoyle features, and angiokeratoma corporis diffusum, meeting the criteria for type I1 fucosidosis. By histochemical and ultrastructural studies, biopsy of rectal mucosa revealed many abnormal macrophages that were filled with fucose-rich granules, and electronmicroscopic examination showed several types of characteristic inclusions in the endothelial cells, fibroblasts, and Schwann's cells.