OBJECTIVES The prevalence of obesity in childhood and adolescence is continuing rising. Macrophage migration inhibitory factor (MIF) participates in inflammatory and immune responses as a pro-inflammatory cytokine. The present study aimed to investigate MIF in overweight adolescents. METHODS Seventy-nine male adolescents were enrolled. Thirty-eight were overweight according to the 90th%ile of the age-specific waist circumference. Various parameters were recorded at one visit, including body mass index. MIF was determined using multiplex immune-assay technology. RESULTS Overweight adolescents had increased systolic blood pressure and CRP levels. Furthermore, increased circulating MIF concentrations were observed (Median: 964.6 pg/ml, Interquartile range: 590.3-2019.4 versus Median: 562.7 pg/ml, Interquartile range: 430.6-813.7, p = 0.003). Increased MIF concentrations were associated with increased markers of inflammation and obesity. CONCLUSIONS We demonstrated elevated MIF levels in obese adolescents. Taken together with other markers, this indicates the presence of low-grade inflammation in these young subjects, possibly representing a link between obesity and related co-morbidities.