Background and Objective: Vitamin D is an important factor for calcium hemostasis, and it is responsible for immune system regulation and lowering the risk of inflammatory disease. The aim of this descriptive study was to evaluate the vitamin D level in patients with rheumatoid arthritis (RA) and analyze its possible relation with the severity or the disease. Materials and Methods: This cross sectional study was performed on 135 patients who met the criteria for rheumatoid arthritis. Data on vitamin D levels from 224 people whom were referred to the Iranian Rheumatism Center laboratory but had turned negative for RA was used as control. Vitamin D levels lower than 30 ng/ml wereconsidered as deficiency, and levels lower than 10 ng/ml were characterized as severe deficiency. Disease status was measured by DAS28 and calculated using the related software. Results: The majority of the patients (82.8%) were female. The mean age of the patients, whom included an 82.8% female participants, was 46.9 years, with a mean disease duration of 9.3 years. The average DAS28 was calculated as 3.47, with an average vitamin D level at 35.9 ng/ml. Vitamin D deficiency and severe deficiency were seen in 59.3% and 8.9% of the patients, respectively. We found no significant relation between the vitamin D levels and disease status. Conclusion: Vitamin D deficiency is common in patients with rheumatoid arthritis but it is does not appear to have a significant relation to the disease status/severity.