OBJECTIVES: To examine annual direct medical & non-medical cost in large-scale rheumatoid arthritis (RA) patient cohort (IORRA) in Japan. METHODS: From patients’ perspective, we calculated direct medical (out-of-pocket costs to hospital & pharmacy and cost for complementary & alternative medicine(CAM)) and non-medical costs (caregiving, transportation,self help devises, house modification) of RA patients, participants of the 15-17th IORRA Studies in Oct. 2007- Oct. 2008. We also assessed correlations between these costs and RA diseaseactivity, disability level and QOL. RESULTS: Data from 5204 RA patients were extracted. Annual direct medical costs were JPY132,000 (out-of-pocket to hospital, USD1=JPY90), JPY84,000 (out-of-pocket to pharmacy) and JPY 146,000 (CAM)), respectively. Annual direct non-medical costs were JPY105,000 (caregiving), JPY22,000 (transportation), JPY30,000 (self help devises) JPY188,000 (house modification), respectively. Considering utilisation rates for each cost component (hospital/pharmacy: 100%, CAM: 31.6%, caregiving: 10.5%, transportation: 100%, self help devices: 21.4%, house modification: 21.4%).  We assumed that annual medical/non-medical cost per RA patient was JPY264,000 and JPY61,000, respectively. These costs increased progressively with worsening RA diseaseactivity, disability level, or QOL. For example, patients with lower Eq-5D score (less than 0.5) spent more money than those with higher one (more than 0.8). Average medical and non-medical costs among them were JPY 30,802 vs. JPY17,887 and JPY229,519 vs. JPY19,536, respectively. CONCLUSIONS: Heavy economic burden lies in RApatients and grows heavier as the disease state is exacerbated using IORRA database. The results also suggest that the increase in medical/non-medical cost may be suppressed by proactively controlling RA.