This article compares the Feighner criteria, the DSM-III criteria for somatization disorder and a modified version of the proposed ICD-10 criteria. Working with a data set collected from the charts of 250 patients considered likely to have unexplained somatic symptoms, the kappa statistic and percentage agreement was calculated. The kappa between the DSM-III and DSM-III-R criteria is 0.93. Between the modified ICD-10 and DSM-III it was 0.71, but between Feighner and the modified ICD-10 it was 0.44. However, the different criteria identify the same patient population based on mental co-morbidity and demographics. The authors suggest that the modified version of the proposed ICD-10 should be investigated further, as it can use data sets previously collected for assessments of somatization disorder.