Maladaptive schemas are stable relational patterns that develop through harmful childhood experiences with primary caregivers. Schemas within somatoform disorders are rarely explored even though these disorders are clinically important due to high prevalence, co-morbidity, and cost for the health care system. This study investigates schemas according to Young's schema theory in patients with somatoform disorders in comparison with healthy controls and patients with depressive or anxiety disorders. Further associations between schemas and somatization were explored. We included 134 patients with a somatoform disorder and 39 age-matched healthy controls, 83 patients with a unipolar depression, and 34 patients with an anxiety disorder. The clinical sample consists of day care patients, diagnosed with the Structured Clinical Interview for Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, but without a personality disorder. Primary measures were the Young Schema Questionnaire (YSQ-S2), the Screening for Somatoform Disorders (SOMS-7T), the Beck Depression Inventory, Second Edition, and the Childhood Trauma Questionnaire. Analyses of variance indicated that somatoform patients scored higher on almost all schemas than do healthy controls (p < 0.001, η2 = 0.148). The highest mean scores were reached for the schemas "self-sacrifice" and "unrelenting standards," with significant higher values in the patient sample. However, when compared with patients with depressive or anxiety disorders, somatoform patients scored equally or even lower. High somatization was associated with generally higher schema activation. This effect was to a great extent mediated by depressive symptoms. Only the schema "vulnerability to harm or illness" was exclusively related to somatization. These findings suggest that schemas should be systematically assessed within psychotherapy of somatoform patients.