Subjects and method: A cross-sectional descriptive study of 41 patients with rheumatoid arthritis in Hue University of Medicine and Pharmacy hospital and 30 healthy people in a control group ư Results: The mean serum IL-6 concentration of the patient group was 120.57 pg / mL which was statistically significantly higher (p < 0.001) than the control group (5.73 pg / mL).