Cells rely on their matrix adhesion complexes to sense multiple environmental cues including extracellular matrix components, adhesive ligand density, surface rigidity and molecular and mechanical perturbations, thus governing their functions and behavior. Label-free and non-invasive biosensors offer generic, integrated, multi-parametric and kinetic measures of cell adhesion and its associated cellular processes. Various label-free biosensor cellular assays are reviewed, and their uses for cell adhesion are discussed. (C) Koninklijke Brill NV, Leiden, 2010