Systems biology is an emerging field that attempts to examine multiple elements of a biologic system using techniques such as expression microarrays or proteomics. The goal of systems biology is to detect all the elements of a system and create an interaction network between these so that the system can be explained under specified conditions. In this review we discuss how systems-based approaches are being applied to cardiovascular disease, illustrating concepts, such as the integration of orthogonal datasets, coexpression networks and emergent properties.