Islet cell autoantibodies (ICA) and other organ-specific autoantibodies were detected in 27 Chinese children with insulin-dependent diabetes mellitus (IDDM). The frequency of ICA within the first year of diagnosis was 67%, and it declined as the duration of the disease increased. The frequencies of thyroid microsomal autoantibodies and gastric parietal cell autoantibodies were 26% and 11%, respectively. None of the patients had adrenal autoantibodies. These results are comparable to those reported in Caucasian patients. Similar frequencies of islet cell autoantibodies and other organ-specific autoantibodies in children with IDDM between Chinese and Caucasians suggest that the autoimmune process may play an important role in the pathogenesis of Chinese children with IDDM.