Abstract Objective To assess serum brain derived neurotrophic factor (BDNF) concentrations as a correlate of cardiopulmonary fitness and as a predictor of cognitive performance in subjects with coronary artery disease (CAD). Methods Serum BDNF concentrations were assayed by ELISA and fitness was assessed using a standardized exercise stress test. The Mini Mental Status Examination (MMSE), California Verbal Learning Test 2nd Ed., Stroop, Trail Making Test B and the Digit Symbol-Coding task were administered. The val66met BDNF genotype and serum interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) concentrations were determined as potential confounders. Results In subjects with CAD (n=88; 85.2% male, mean age 62.8±10.5yr), cardiopulmonary fitness was associated with higher serum BDNF concentrations (β=.305, p=.013). Higher serum BDNF concentrations were associated with higher MMSE scores (F(1,87)=15.406, p<.0005) and better performance on the Digit Symbol-Coding task (F(1,87)=9.620, p=.003). IL-6, TNF-α and the val66met genotype did not influence these results. Conclusion Serum BDNF concentrations were associated with cardiopulmonary fitness, psychomotor processing speed and overall cognition in subjects with CAD.