Introduction: C-reactive protein (CRP) is a marker of chronic systemic inflammation frequently used in cardiovascular disease risk assessment. The aim of this study was to investigate CRP concentrations in middle-aged men after 8 weeks high intensity aerobic exercise. Material & Methods: Twenty two sedentary obese middle-aged men (aged: 46.4 ± 2.3 years and body mass index (BMI): 32.8 ± 2.0 kg/m2; ± SD) volunteered to participate in this study. The subjects were randomly assigned to training group (n=11) or control group (n=11). The training group performed high intensity aerobic training 3 days a week for 8 weeks at an intensity corresponding to 75-80% individual maximum oxygen consumption for 45 min. Results: The results showed that the body weight, BMI, body fat percent and WHR were decreased and VO2max was increased in the training group compared to the control group (P<0.05). After 8 weeks, the training group resulted in a significant decrease (58.7 %) in the CRP in compared with the control group. Conclusions: The results suggest high intensity aerobic exercise improves body composition and decreases CRP concentrations in obese middle-aged men. Manuscript profile