Background and objectives: This study attempts to assess the intensity and quality of pain and health-related quality of life in patients with sacroiliac syndrome and to compare those constructs to patients with lumbar radiculopathy. Methods: A retrospective review of patient records with the diagnosis of sacroiliac syndrome or lumbar radiculopathy was performed. Patients with sacroiliac syndrome were age and gender matched to patients with lumbar radiculopathy. Data from the McGill Pain Questionnaire, visual numerical pain scores, and SF-36 health-related quality of life measure (version 2) were compared between groups. Results: The age of patients with a traumatic etiology for sacroiliac syndrome was lower than those with previous back surgery and "idiopathic" etiologies (P < .02). Duration of pain in patients with "idiopathic" etiology was longer in comparison to those with previous back surgery (P < .005). No statistical difference occurred between patients with sacroiliac syndrome and lumbar radiculopathy with respect to McGill pain scores, visual numerical pain scores, and SF-36 health-related quality of life measure. Conclusions: The results of this study suggest the following: (1) no true difference exists in the health-related quality of life or pain scores/descriptors between patients with SI syndrome or lumbar radiculopathy, or (2) the presence of comorbid spinal conditions confounds the ability of the SF-36 to detect disparities in health-related quality of life among differing etiologies of low-back pain, despite the use of rigorous diagnostic criteria, and/or (3) other factors besides the diagnostic categories of low-back pain (e.g., functional capability, psychological stress) may be primary determinants of health-related quality of life. To our knowledge, no other study has attempted to use the SF-36 to detect differences in health-related quality of life among patients with different spinal diagnoses.