Objectives: To elucidate the association between metabolic syndrome (MetS) and disability due to low back pain (LBP) among care workers. Material and Methods: This cross-sectional study enrolled 656 care workers having experienced LBP in the year prior to the year of this study. The Roland-Morris Disability questionnaire (RDQ) and self-reported questionnaires regarding LBP, fear of movement, depressive symptom, psychosocial factors, intensity of pain, and duration of pain were administered, and a medical examination was performed. Metabolic syndrome was defined according to the international definition agreed in 2009. Out of the 656 care workers, we included 316 care workers (response rate: 48.2%) who had fully completed the questionnaires as the study sample (males: 13.6%, median age = 51 years old, range: 35–74 years old). To examine the association between MetS and the level of disability due to LBP, we used the Poisson regression analysis and estimated crude and adjusted prevalence ratios (PR). Results: Out of the 316 care workers, 52 (16.5%) were diagnosed as having MetS. Metabolic syndrome was significantly associated with the RDQ score (adjusted PR: 1.57, 95% confidence interval (CI): 1.17–2.11) after adjusting for covariates, such as age, sex, fear of movement, job demands, social support, intensity of pain, and duration of pain. Conclusions: This study showed that MetS was independently associated with disability due to LBP among care workers. A multidisciplinary intervention taking MetS into consideration may be an effective way to reduce disability due to LBP in people with both LBP and MetS. Int J Occup Med Environ Health 2018;31(2):165–172