This study examined how somatization disorder relates to physical and psychosocial measures for patients with chronic lower-extremity osteoarthritis (OA). A cohort of 421 patients with lower-extremity OA of the hip or knee consented to preoperative evaluations. The Patient Health Questionnaire was administered to identify patients with and without somatization disorder. Analyses were conducted to determine differences between demographic and preoperative physical and psychosocial variables. Patients with somatization disorder scored significantly worse on measures of pain, stiffness, function, perceived disability, and quality of life measures. Somatization disorder can have profound effects on patients’ physical and psychosocial measures. Recommended treatment for chronic pain patients often includes using a biopsychosocial approach, which involves treating both the psychological state along with the pain condition.