Three patients are presented, who by electron microscopy, showed prominent fibrillary deposits in the glomeruli, and in two, also around the tubules. By immunohistology these two cases had no immunoglobulins in either glomeruli or around the tubules. In the third case, which probably represents a slightly different form of the disease, minor deposits of IgM were found in the glomeruli, while fibrillary deposits were extensive and widespread. It is suggested that precursors of fibrillary deposits may not be the same in all cases.