1. Fibroblasts were cultured from four patients, two patients from two independent family lines, clinically diagnosed as familial Alzheimer's disease. 2. Adhesion efficiency to the dish was significantly suppressed with fibroblasts from patients with familial Alzheimer's disease compared with the cells from the age-matched control. 3. Cytoskeletal systems were visualized by immunofluorescent staining with antibodies against tubulin, actin, and vimentin, showing unique dearrangement of vimentin fibers in fibroblasts from familial Alzheimer's disease. 4. Regrowth of vimentin fibers after colchicine treatment was slower with fibroblasts from familial Alzheimer's disease than that of the control. 5. Western blotting analysis showed no change in tubulin, actin, and vimentin, but the size of fodrin in familial Alzheimer fibroblasts were different from that of the control cell.