Objective: The present study explores the link between reported sexual and/or physical abuse and psychological defense styles, as well as the association of both with psychological distress in adulthood. In two patient samples that differ in psychological distress and somatization, we examine whether the adversities reported and immature defense styles are associated with psychopathological symptoms. Method: We examined 266 consecutive inpatients in the psychosomatic department and 109 consecutive inpatients who had been treated for low-back pain in the orthopedic department of a German university hospital. Psychological defense styles were assessed by a two-factor solution of the German modified adaptation of the Defense Mechanism Inventory (DMI), childhood adversities by a structured interview, psychological distress by the SCL-90-R, and somatization by the Screening for Somatoform Disorders (SOMS). Results: Both samples demonstrated a significant link between immature defense styles and the extent of overall psychological distress as well as somatization. Reported sexual and/or physical abuse of patients in both patient samples was directly associated with somatization. Conclusion: Recollections of sexual and/or physical abuse in childhood and immature defense styles have an association with psychopathology in adulthood. This finding suggests that immature defense styles may act, in part, as mediators between the adversities investigated and adult psychopathology.