The objective of this study was to further evaluate the efficacy of selenium supplementation in patients with rheumatoid arthritis, aiming to provide more reliable evidence-based support for nutritional supplementation in these patients.Four databases, the Cochrane Library, Web of Science, PubMed and Embase, were searched for only randomized controlled trials on selenium supplementation in patients with rheumatoid arthritis. The search date ranged from the build date to February 12, 2025. The literature was screened by two researchers according to the appropriate criteria. The assessment of the quality of the studies was conducted using Risk of Bias 2.0. The data were analyzed in this study using RevMan 5.4.Seven studies including a total of 367 patients with rheumatoid arthritis were included in the study. The results showed that selenium supplementation was effective in reducing the VAS score (MD = -12.68, 95 % CI [-19.08, - 6.28], P = 0.0001) and the Ritchie index (MD = -1.13, 95 % CI [-2.22, - 0.05], P = 0.04) in patients with RA. However, selenium supplementation in patients with rheumatoid arthritis reduced the erythrocyte sedimentation rate (MD = - 8.87, 95 % CI [-3.60, 1.85], P = 0.53), and the C-reactive protein levels (MD = - 0.67, 95 % CI [-1.43, 0.1], P = 0.09), relieved morning stiffness (MD = 0.00, 95 % CI [-0.13, 0.13], P = 0.95), and joint swelling (MD = - 0.06, 95 % CI [-0.54, 0.42], P = 0.81) but these effects were not statistically significant.Meta-analysis revealed that selenium supplementation has beneficial effects on joint pain in patients with rheumatoid arthritis. However, further clinical trials are needed to elucidate its effects on the erythrocyte sedimentation rate, C-reactive protein levels, morning stiffness, and joint swelling in rheumatoid arthritis patients.Copyright © 2025. Published by Elsevier GmbH.