Biodiversity reaches its zenith in the tropics. At the same time, tropical cities are growing dramatically and usually with a low capacity for planning and management for biological conservation. A better knowledge of the ecology of these cities is essential to avoid or at least reduce the impacts of rapid urbanization on nature, to conserve biodiversity and to guarantee access to the benefits of nature— their ecosystem services—to citizens. However, a huge scientific bias is evident. While we know that the the biological diversity of the tropics is relatively poorly studied, and the biodiversity and resultating ecology of tropical cities is even less well understood. In this chapter, we will present the book, its two volumes, its objectives and the main themes covered throughout its four parts.