Optical systems which have stringent reouirements on stray light levels often need optical baffles. Some basic design principles and goals for baffles are Presented. Four generic optical designs and their advantages for stray light control are discussed: all reflective and all refractive reimaging and nonreimaging systems. The desirable shape and location of baffle vanes are shown, based on various design criteria. Presuming that the designer has the ability to control specular reflections from baffle surfaces, absorptive coatings which reflect specularly are preferred over those which reflect diffusely. Stray energy from edge diffraction can be controlled in a nonreimaging optical system by forcing light to undergo multiple diffractions.