Newly developed proteomic technologies now permit the routine identification of hundreds or even thousands of proteins in a single experiment. However, the global study of any proteome has unique challenges that set it apart from comprehensive studies of genes and transcripts. The detection of low-abundance, biologically relevant proteins poses a particular challenge, especially given that the dynamic range of proteins in cells is estimated to be > or =10(6). Nevertheless, the incorporation of proteomics into functional biochemical and biologic investigation has proved to be a powerful tool when applied to platelet biology. This review highlights recent proteomic approaches to the characterization of the proteins released from activated platelets and to the identification of integrin-associated regulators of platelet function. Also described are efforts to link platelet-proteomic and platelet-transcriptional data.