The thrombospondins are a family of extracellular proteins that participate in cell-to-cell and cell-to-matrix communication. They regulate cellular phenotype during tissue genesis and repair. Five family members, each representing a separate gene product, probably exist in most vertebrate species. Like most extracellular proteins, the thrombospondins are composed of several structural domains that are responsible for the numerous biological functions that have been described for this protein family. Considerable progress has been made towards understanding the function of thrombospondins. The role of thrombospondin in the process of apoptosis or programmed cell death has recently come into focus. In this review we will concentrate on the role of thrombospondin-1 in the broad field of apoptotis research.