Background: Lateral epicondylitis (LE) is a common musculoskeletal condition. However, the treatment of LE is still controversial. The present study evaluated the production of inflammatory cytokines by lateral epicondylitis-derived cells and compared the anti-inflammatory effect of triamcinolone acetonide with platelet-rich plasma (PRP) on their production in cell culture.Methods: Third passage cells from primary cultures of lateral epicondylitis were assessed for the production of the cytokines IL-1β, IL-6, IL-8, IL-10 and TNF-α by immune-enzymatic assay (ELISA), after treatment with 1, 10 and 100 mM triamcinolone compared to untreated controls at the time points 6, 12, 18, 24, 48, 72 and 96 hours, and to PRP at 48, 72 and 96 hours.Results: The cytokines IL-6 and IL-8 were produced in high concentrations by lateral epicondylitis cells. Triamcinolone induced a significant decrease in the production of IL-6 and IL-8 at 48, 72 and 96 hours, and at 12 hours for IL-8. The PRP group produced significantly higher levels of IL-8 than the control group, at 96 hours. There was a significant increase in IL-10 production with the use of 100 μM triamcinolone at 48 hours, compared to controls. The production of IL1-β and TNF-α was very low and did not change when the cultures were treated with triamcinolone or PRP.Conclusion: Our results demonstrated that IL-6 and IL-8 plays a role in the pathogenesis of lateral epicondylitis. Triamcinolone inhibited the production of the production of IL-6 and IL-8 by lateral epicondylitis-derived cells and PRP induced an increase in IL-8 levels compared to controls.