The aim of this study was to evaluate the effects of orthodontic treatment on systemic levels of the inflammatory markers, C-reactive protein (CRP), tumour necrosis factor-alpha (TNF-alpha), and interleukin-6 (IL-6). The study group comprised 11 girls and 6 boys (mean age 13.1 years) treated with fixed appliances and distalizing headgear. Venous blood samples were taken from the cubital vein of each subject before treatment (T0) and then at three further time points during treatment (T1-T3), 2 months apart. The sera from these blood samples were analysed using enzyme-linked immunosorbent assay (ELISA) assay technology for CRP, TNF-alpha, and IL-6 concentration levels. Data were compared between baseline and subsequent sequential time points using a Mann-Whitney test for non-normally distributed variables. The results showed that there was no significant elevation of any of the three inflammatory markers at any of the time points. This research provides evidence that conventional orthodontic treatment is not associated with a systemic immune response in the factors investigated.