One impediment to detailed characterization of islet-specific T cells from the NOD mouse model of diabetes is the difficulty encountered in isolation of such cells. This report describes a method that allows routine isolation of relatively large numbers of T cells highly enriched for reactivity toward islet antigens. The method involves renal subcapsular transplantation of spontaneously diabetic NOD mice with NOD islets. These grafts are rapidly destroyed in a tissue-specific manner and this destruction is accompanied by lymphocytic infiltration. Here we demonstrate that the islet graft infiltrates are an excellent source of islet-specific T cells and that islet-specific T-cell lines and clones can be established from these cells. Islet-specific T-cell clones isolated from a T-cell line established from the islet graft infiltrates were capable of adoptive transfer of diabetes to NOD/LtSz-scid recipients.