Objective: To clarify the relationship between cognitive impairment and the physical function of elderly patients with rheumatoid arthritis（RA）.

Subjects and Methods: Fifty-two RA patients of ≥ 65 years of age with pre-frailty or frailty were hospitalized for 3 nights and 4 days, and individual exercise and nutritional guidance were provided in conjunction with assessments of their physical and cognitive functions. Grip strength, gait speed, and skeletal muscle index（SMI）were re-examined at 6 and 12 months after discharge. Patients with a mini mental state examination（MMSE）score of ≤ 27 points were classified into the mild cognitive impairment（MCI）group（n=27）and compared with the non-MCI group（n=25）. Changes over time in both groups were compared using a two-way analysis of variance.

Results: The MCI group had weaker grip strength, slower gait speed, shorter stride length, and a longer timed up-and-go test（TUG）than the non-MCI group. Regarding changes over time, only walking speed showed a significant improvement while other items remained unchanged.

Conclusion: The decline in the physical function tended to be advanced when cognitive impairment was observed in elderly patients with RA. Early intervention is important for preventing the decline of the cognitive and physical functions of patients with cognitive impairment.