In the present study, the potential role of alexithymia in predicting the long-term treatment outcome was investigated prospectively in 30 patients with DSM-III-R somatoform disorders and anxiety disorders. Using SCID interviews, diagnoses were assessed before inpatient treatment and 2 years after discharge. Patients who met criteria for DSM-III-R undifferentiated somatoform disorder at follow-up exhibited higher pretreatment alexithymia scores (as measured by the TAS) as compared with patients who showed remission of their somatoform disorder or patients who never had met criteria for a somatoform disorder. As a result stepwise logistic regression analyses, high alexithymia scores emerged as a significant predictor of persistent somatization, independent of other measures of psychopathology, sociodemographic variables, and measures of illness severity.