The intravital microscopy in the mouse cremaster muscle microcirculation is a method widely used to visualize in vivo blood cells interacting with the endothelium and within the vessels. Therefore, it is a suitable technique to study leukocyte-endothelial cell interactions along every stage of the canonical leukocyte recruitment cascade: rolling, adhesion, intravascular crawling, and migration both in postcapillary venules and arterioles of the mouse cremasteric microcirculation. This technique also enables to assess vessel functionality, since hemodynamic parameters such as shear stress, flow rate, and vasodilatation/vasoconstriction, among other vascular events, can be additionally determined. Furthermore, response to multiple drugs and mechanisms underlying blood cells interactions within the vascular system can be studied in a real scenario. This chapter describes a protocol for intravital microscopy in the mouse cremaster muscle microcirculation.