Because of environmental and business factors, reverse logistics has received increasing attention in many industries. This chapter will offer a comprehensive investigation into reverse logistics and related subjects. After introducing the subject and providing a literature review related to reverse logistics in recent papers, three main questions are studied: Why are things returned? How are they returned? What things are returned? We also investigate reverse logistics’ application and its relationship with the vehicle-routing problem and information technology. Finally, we study the quantitative models in this area.