Prospective study. To identify relationships between spinopelvic parameters and health-related quality of life in rheumatoid arthritis (RA). Little data are available on relationships between sagittal spinopelvic parameters and health-related quality of life in RA. The study and control groups comprised 120 RA patients and 60 controls. All subjects underwent anteroposterior and lateral radiography of the whole spine, including hip joints, and all completed clinical questionnaires. The radiographic parameters examined were: sacral slope, pelvic tilt, pelvic incidence, thoracic kyphosis, lumbar lordosis, C7/sacrofemoral distance ratio (C7/SFD), and spinosacral angle (SSA). Quality of life was assessed using a Visual Analog Scale for back pain, the Oswestry disability index questionnaire, and the Scoliosis Research Society (SRS-22) questionnaire. Statistical analysis was performed to identify significant differences between the study and control groups. In addition, correlations between radiologic parameters and clinical questionnaires were sought. The patients and controls were found to be significantly different in terms of sacral slope, pelvic tilt, lumbar lordosis, thoracic kyphosis, C7/SFD, and SSA, but not for pelvic incidence (P>0.05). Correlation analysis revealed significant relationships between radiographic parameters and clinical outcomes. Multiple regression analysis was performed to identify predictors of clinical outcome, and the results obtained revealed that C7/SFD significantly predicted Visual Analog Scale score and SSA predicted Oswestry disability index and SRS-22 scores. Sagittal spinopelvic parameters were found to be significantly different in RA patients and normal controls. Correlation analysis revealed significant relationships between radiographic parameters and clinical outcomes. In particular, C7/SFD and SSA were found to be significant predictors of clinical outcomes in RA.