Somatizing patients -- those presenting to physicians with multiple medically unexplained physical complaints - constitute an important and vexing problem for the primary health care system. Patients with this syndrome use health care resources extensively but receive little benefit. In addition, these patients experience significant distress and disability. To date, no medical or psychiatric intervention has been demonstrated in controlled trials, to produce clinically significant and lasting symptom relief or improved functional status in these patients. We propose herein a randomized controlled trial (N=240) of cognitive behavior therapy (CBT) versus medical care-as-usual for primary care patients with high levels of medically unexplained somatic symptoms (patients who meet DSM-IV criteria for a Somatoform Disorder as well as 'minimum symptom thresholds for Escobar's """"""""abridged somatization""""""""). The intervention will take place at primary care sites as somatizers are often reluctant to use psychiatric services or even admit to psychiatric problems. In proposing this research, we are encouraged by the positive results of several uncontrolled trials of CBT for somatization, including a pilot test of our own manualized intervention. A secondary aim of the proposed work is to examine the effectiveness of the CBT protocol for a Latino sample, because high levels of unexplained physical symptoms are quite prominent in many subgroups of Latinos. Moreover, Latinos are the fastest growing minority population in the U.S., and are projected to account for 24.5% of the total U.S. population by the year 2050, from 10.5% currently (Bureau of the Census, 1996). In spite of the relatively high prevalence of somatization in this group, to our knowledge, there are no controlled trials of the effectiveness of treatments for somatization in the Latino community.