Background/Aim: In adults, studies have shown that obesity is a chronic low-grade inflammatory state characterized by altered levels of cytokines. Studies in children have mainly focused on C-reactive protein and adiponectin, and there is limited data for other inflammatory markers in healthy weight and overweight children. The aim of this study was to measure IL-6, IL-8 and IL-10 levels in healthy normal weight and overweight children at 8 and 15 years. Methods: 118 normal weight and overweight children (59 boys) from the Nepean longitudinal study were recruited at age 8 years and followed up at 15 years. Serum IL-6, IL-8 and IL-10 levels were measured at both time-points. Results: At 8 years, we found no significant differences in cytokine levels between normal weight and overweight (owt)/obese (ob) groups. However, at 15 years, owt/ob girls (n = 23) had higher levels of IL-6 (p = 0.04), IL-8 (p = 0.04) and IL-10 (p = 0.03) compared to normal weight girls (n = 36), even after adjustment for puberty; no differences were seen in boys. Conclusion:The effects of obesity on IL-6, IL-8 and IL-10 levels vary with age and sex, with owt/ob girls at 15 years showing raised IL-6, IL-8 and IL-10 levels compared to healthy weight girls.