One of the most important properties of cells that are derived from multicellular organisms is their ability to adhere to extracellular matrix proteins or other cells. Analysis of cell-extracellular matrix and/or cell-cell adhesion, therefore, is of important value to experimental biologists as well as clinical investigators. Over the past several decades, many different cell-adhesion assays have been developed. Based on the experimental conditions, most of the cell-adhesion assays fall into two categories, namely static adhesion assays and flow adhesion assays. Static assays are widely used to assess the adhesion of many types of cells (e.g., epithelial cells and fibroblasts) to the extracellular matrix. The flow adhesion assays are more appropriate for analysis of blood cell (e.g., leukocyte) adhesion to endothelial cells, to each other, or extracellular matrix proteins. This chapter describes two basic protocols, one for analysis of cell adhesion under static conditions and the other for measurement of cell adhesion under shear stress. In addition, variations to the basic protocols and areas where special attention is required for successful application of these methods are discussed.