Urban population growth, consequent competition in land use, climate change and lack of productive resources are some of the problems that are currently making necessary a new form of agriculture free from soil exploitation and able to ensure food security to urban dwellers in the most sustainable way. Rooftop farming is a form of building-base agriculture that may help to address not only global nutritional uncertainty, but also social, environmental and economic issues such as social exclusion, heat island effect, storm water damages and urban poverty. This chapter describes the forms, architecture, design elements and management of rooftop farming, as well as presenting case studies from around the world. Finally, the chapter looks ahead to future research trends in this area.