To keep a child’s mouth in optimum health and usefulness is the duty and responsibility of every dentist. In the quest for providing optimal dental care, the age – old maxim of ‘prevention is better than cure’ holds true. In this endeavor the pedodontist is most evenly poised to carry the mantle of providing the required services. One of the most important services is that of maintaining arch length prior to the eruption of the permanent teeth. It should be the goal of every practitioner providing oral health care for children and adolescents to assess and guide the developing occlusion toward optimum outcomes. Hence the present article reviews in general regarding the space maintainer.