According to the demographic and clinical data of the COPD cases, we observed a statistically significant negative correlation of BDNF serum levels with the age of enrollment of the patients in this study (Rho = −0.279, p = 0.036, Spearman correlation test), and a marginal negative correlation with the age of disease onset (Rho = −0.244, p = 0.063, Spearman correlation test). This evidence concerns the gene BDNF and chronic obstructive pulmonary disease.