Proteomics involves the integration of a number of technologies with the aim of analyzing the complete complement of proteins expressed by a biological system in response to various stimuli and/or under different physiological or pathophysiological conditions. Recent technical improvements to the methods employed for protein separation and protein identification have resulted in a dramatic increase in the number of proteomics-based research projects. More importantly, it has become readily apparent that examining changes in the proteome offers insight into understanding cellular and molecular mechanisms that cannot be obtained through genomic analysis. There are numerous examples of cardiovascular functions whose molecular pathways are mediated through post-translational processes such as phosphorylation. The use of proteomics offers the ability to simultaneously monitor the changes in protein expression and/or cell signaling pathways in response to such conditions as cardiac hypertrophy and heart failure. Together with complementary genomic data, proteomics-based research can greatly increase our understanding of cardiovascular biology.