The goals of this study were to determine 1) the occurrence of various dissociative phenomena in patients with somatization disorder, 2) the occurrence of six different types of childhood interpersonal trauma in these patients, and 3) the nature of these patients' early family environment. Twenty-two patients with somatization disorder and 19 medical comparison subjects completed the Structured Clinical Interview for DSM-IV Dissociative Disorders, the Childhood Trauma Interview, and the Family Functioning Scale. The somatization disorder patients reported significantly higher level of dissociative amnesia than the comparison subjects. The two groups reported similar levels of depersonalization, derealization, identity confusion, and identity alteration. Somatization disorder patients reported significantly greater childhood emotional abuse and more severe forms of physical abuse, relative to the comparison subjects, with chronic emotional abuse being the best predictor of unexplained symptoms. Childhood sexual abuse, separation/loss, and witnessing violence were equally common in the two groups. The somatization disorder group reported significantly more family conflict and less family cohesion. Only some types of dissociation are more severe in patients with somatization disorder, relative to medical comparison subjects. Many patients with somatization disorder are raised in an emotionally cold, distant, and unsupportive family environment characterized by chronic emotional and physical abuse. Sexual abuse is not a necessary prerequisite for the disorder.