This study designed to evaluate the relationship between the Matrix metalloproteinase -9(MMP-9), soluble Vascular endothelial cadherin(VE-CAD)and Chlamydia pneumonia infection in cardiovascular diseases patients. All blood sample were subjected for molecular detection of C.pneumoniae by using conventional polymerase chain reaction (PCR) depending on 16S rRNA while the level of serum MMP-9, VE-CAD measured by enzyme linked immunosorbent assay (ELISA). Seventy patients who suffering from cardiovascular diseases (angina, myocardial infraction and atherosclerosis) aged between 33-86 years have been investigated and compared to twenty of apparently healthy individuals as control group. Twenty six samples (37.14%) revealed positive results for C. pneumoniae by PCR technique in blood samples of patient group, while all control samples were negative, furthermore current study revealed a highly significant elevation (p<0.01) in the mean concentration of VE-CAD and significant elevation (p<0.05) in the mean concentration of MMP-9 in sera of patients with CVD compared to control group also there were significant differences in the level of serum MMP-9, VE-CAD between C. pneumoniae positive and negative within the patients group. The present study concludes there is a significant proportion among CVD patients were infected with C.pneumoniae and the bacterium could be contributes in pathogenesis of CVD and endothelial dysfunction through stimulation of the inflammatory response and degradation of adhesion molecules in addition to the extracellular matrix.