With the developing technology and increasing urbanization, many problems have started to arise in the use of energy resources and in our natural environment. Energy-saving constitutes the main purpose of any proposed smart system. In addition, environmental effects should be taken into consideration. In an outdoor lighting, along with the use of energy-efficient bulbs, the lighting should be done with the right method and in the right way. In addition to these, an intelligent system integrated with an automatic control mechanism is needed. Incorrect outdoor lighting causes unnecessary energy consumption as well as light pollution and CO2 emission. These situations have negative consequences on both the mental and physical health of the human being, as well as on other living things and nature. Therefore, smart outdoor lighting systems offer an essential solution in preventing negative consequences that may occur with incorrect outdoor lighting. In this study, outdoor lighting requirements, light pollution and smart cities have been examined in detail and the smart outdoor lighting systems within the scope of smart cities are emphasized. As a result, it has been seen how important and necessary is the smart outdoor lighting system, which provides an energy-efficient and environmentally friendly structure by enabling street lamps to work smartly and efficiently.