Starting from a group of 736 renal biopsy patients, evaluated by ultrastructural studies over a period of 22 years, the authors present a rare case of immunotactoid glomerulopathy, suggesting that these forms, until a few years ago considered in the same group as fibrillary glomerulonephritis, are in fact a separate entity; moreover, they may represent a very early manifestation of plasmacellular dyscrasia still at the initial stage.