Background: The purpose of this study was to evaluate plasma pentraxin 3 (PTX3) and growth differentiation factor-15 (GDF-15) concentrations in adolescent male swimmers and compare any possible interactions with canonical biochemical parameters. METHODS: Twenty-six adolescent male swimmers and 29 gender- and age-matched sedentary controls participated in this study. Fasting blood samples were taken from the participants. Biochemical values and plasma PTX3 and GDF-15 levels were measured. RESULTS: Plasma PTX-3 levels were markedly higher in the adolescent male swimmers than in the sedentary controls (378.44 ± 173.93 vs 257.82 ± 103.20 pg mL-1, p = 0.002). There was no significant difference in GDF-15 levels between the two groups (186.12 ± 40.65 vs 203.60 ± 36.77 pg mL-1 in the swimmers and the sedentary, respectively, P = 0.068). Relationship between PTX3 and GDF-15 was linear. CONCLUSIONS: This is the first study showing that adolescent male swimmers have higher PTX3 levels than sedentary controls and that there is a linear relationship between PTX3 and GDF-15.