In any optical system, no matter how simple or complex, each optical element must be mounted in some way. Furthermore, system performance depends on the precision of the optics, their mounts, and their positioning accuracy. Optomechanical mounts may seem like insignificant design elements, but they can make or break a photonics application. Thus, designers should pay the same attention to optomechanical mount selection as to tolerancing individual optical elements. Typically, the most important parameters in determining the performance of optomechanical mounts are adjustment range, resolution, repeatability, orthogonality of motion, stability, thermal drift and cost. Understanding these parameters and individual mount mechanisms can help a designer select the right mounts for a given application.