The thrombospondins are a 5-member gene family that mediate cell-cell and cell-matrix interactions. The thrombospondins are either trimers or pentamers, and their functions depend on their abilities to interact with numerous extracellular ligands and cell surface receptors through the multiple domains that compose each subunit. Recent genetic studies have indicated associations of particular single nucleotide polymorphisms in 3 of the 5 thrombospondins with cardiovascular disease. This observation has stimulated efforts to understand how the thrombospondins influence cardiovascular pathology, to dissect how the individual polymorphisms alter the structure and function of the parent thrombospondin molecules, and to replicate the genetic data in different patient populations. This review seeks to summarize current information that has emerged on each of these fronts.