An attempt has been made to induce intercapillary glomerulosclerosis in rabbits by immunization with insulin incorporated in Freund's adjuvant and followed by repeated challenges with subcutaneously given insulin. It was observed that lesions resembling human diabetic glomerulosclerosis with occasional nodule-like formation could be produced and that the challenge insulin injections produced proteinuria. The presence of a delayed type of hypersensitivity seemed necessary for the lesions to occur as did the dissemination of the immunizing material to the kidneys. The experiment also disclosed that intravenously given DIS-tagged insulin localizes in a subtly different kind of glomerular lesion with different staining properties. The significance of these findings and the possible role of insulin treatment in the pathogenesis of human diabetic glomerulosclerosis is discussed.