The pathogenic effect of antitubular basement membrane (TBM) antibodies in anti-TBM interstitial nephritis has been demonstrated. To determine the relative role of sensitized cells in inducing this lesion, lymph node cells (LNC) alone or a combination of LNC and peritoneal exudate cells were transferred from Brown Norway (BN) rats, previously immunized with TBM into unimmunized BN-recipient rats. Cells were transferred directly under the recipients' renal capsules. Although significant tubular lesions were induced by the cells, the lesions were usually mild and always focal. Hence, sensitized cells do not appear to be central to the pathogenesis of anti-TBM nephritis.