Intravital microscopy is a method to study the microcirculation in living tissues. Transillumination, oblique reflected light illumination, continuous and stroboscopic epifluorescence microscopy can be used to visualized specific cells and molecules. Intravital microscopy is further enhanced by the advent of laser scanning.spinning disk confocal and multi-photon microscopy. Recent advances include blood-perfused flow chambers and microfluidic devises for the study of blood cell interactions with molecularly defined substrates. This chapter focuses on the application of these techniques to study leukocyte interactions with the vascular wall and molecular surfaces.