Sera from 46 newly diagnosed type 1 diabetic patients and from 100 normal controls were screened for ICA Cf ICA (standard immunofluorescence test) and for ICSA (ELISA assay) detection. Among 46 patients, 33 (71.7%) were ICA positive (16 of them also Cf ICA positive) and 21 resulted ICSA positive (45%). No correlation was found between ICSA, ICA and Cf ICA respectively. Therefore the ICSA detection, by a new and sensitive ELISA assay, in addition to ICA immunofluorescence determination, may be of significant diagnostic value in IDDM of recent onset.