During activation, blood cells experience changes in intracellular free calcium levels ([Ca2+]i) that are associated with signal transduction events. In granulocytic cells, changes in [Ca2+]i have been associated with multiple functions, including activation of cellular kinases and phosphatases, degranulation, phagosome-lysosome fusion, regulation of cytoskeletal binding proteins, transcriptional control, and modulation of surface receptors. This review discusses the general role played by [Ca2+]i in granulocytic leukocyte signal transduction, with a special emphasis on recent developments in the field of calcium signaling to and from integrins and the regulation of cell adhesion and motility by [Ca2+]i.