Integrins are a family of cell adhesion receptors that support and modulate a variety of cellular functions that are required for tumor metastasis. Integrins expressed by tumor cells and host cells can directly contribute to the control and progress of metastatic dissemination. During tumor development, changes in integrin expression, intracellular control of integrin functions and signals perceived from integrin ligand binding impact upon the ability of tumor cells to interact with their environment and enable metastatic cells to convert from a sessile, stationary to a migratory and invasive phenotype. Integrins are involved in each step of the metastatic cascade and affect tumor cell survival and interaction with changing environments in transit from the primary tumor to distant target organs.