Background: Rheumatoid arthritis (RA) is a chronic inflammatory condition affecting joints. It is managed with pharmacological therapies, but it is speculated that dietary intervention may be of significant benefit to patients in helping to manage the condition alongside their medication. This may be mediated through effects on levels of chronic inflammation and thus can influence disease activity. Previous research has indicated the potential of diet to aid in the condition’s management, but a comprehensive review is required to pull together the evidence. Objective: Conduct a systematic review of existing literature on the impact of differing dietary interventions on disease activity and inflammatory status in rheumatoid arthritis patients. Then draw conclusions about the strength of evidence and identify patterns amongst identified papers in a narrative synthesis. Methods: The existing literature was searched according to a pre-determined search strategy, using the databases PubMed, Embase and MEDLINE. Data was then extracted according to a template and results related in a narrative synthesis. Meta-analysis was not conducted. Results: Eight studies, all randomised controlled trials, were included in the review. Outcomes included disease activity score 28 and inflammatory markers such as erythrocyte sedimentation rate and C-reactive protein. Dietary patterns such as an anti-inflammatory diet showed inconclusive evidence with regards to impact on disease outcomes. Strong evidence for the reduction of inflammation and disease activity was demonstrated in studies investigating probiotic supplementation. Conclusion: Results demonstrated the ability of probiotics to have a beneficial impact for RA patients, which may allow healthcare professionals to develop treatment plans and advice including this intervention. However more research should be conducted in different regions and in combination with other interventions to further the understanding of its effects and safety. Other dietary interventions included showed significant associations for some outcomes and not others. Therefore, further research should be conducted to determine whether they are feasible for use in the management of RA patients.