Despite the low prevalence of somatization disorder in the community, the section of the Diagnostic Interview Schedule used to make the diagnosis-as well as previous diagnostic interviews for the related diagnoses of hysteria, and Briquet's syndrome-is quite lengthy. This study evaluates a somatization disorder screening index derived from completed interviews from the NIMH sponsored Epidemiologic Catchment Area program. A screening index comprised of 11 symptoms of somatization was derived at the Duke ECA site and replicated across the Johns Hopkins, Yale, and Washington University sites. Across ECA sites a screening threshold of five of 11 symptoms correctly identified 41 of 42 respondents with DIS/DSM-III somatization disorder (97.6%) while correctly classifying 14,600 of 14,750 (99.0%) without the disorder. The screening index offers promise as a screening device for clinical and community studies of somatization disorder.