Objective: to evaluate whether the values of the modified disease activity score (mDAS28), the simplified disease activity index (SDAI) and the clinical disease activity (CDAI) are in congruence with the disease activity score including a 28-joint count (DAS28) disease activity criteria to obtain a clear assessment of the patient's overall disease activity. Patients and methods: this study included 100 rheumatoid arthritis patients which had fulfilled the criteria of American college of Rheumatology for diagnosis of RA. All patients were subjected to assessment of disease activity using DAS28, mDAS28, SDAI and CDAI. Results: The 94 female and 6 male patients were of a mean age of 50.23±10.79 (23–73) and have been living with RA for a mean of (2 months–41 years). The DAS28 mean score was 5.92±1.19 [3.56–8.38]. The mDAS28 mean score was 4.97±0.96 [2.95–6.94]. The CDAI mean score was32.44±15.34 [8–70] and that of SDAI was 46.14±19.73 [15–102]. On a group level, a positive, statistically significant correlation was noted between the four indices of RA activity as P value are always 0.000 (P<0.001). The level of similarity between the different indices was good (K variation between 0.799 and 0.936). Conclusion: Different evaluation indices of RA activity are currently available. DAS28 is the most used. CDAI and especially SDAI have a good level of similarity with DAS28. Their advantage is to be simple and quick, and seem therefore well adapted to the follow-up of outpatients. The mDAS28 is a valid and sensitive tool to assess disease activity, as an alternative to the DAS28, when acute-phase reactant values are unavailable.