In this chapter, we explored the main negative effects of human-related structures, such as pervasive road networks, on animal reproductive fitness. Briefly, we know that roads massively reduce insect, amphibian, reptile, bird, and mammal populations at some stage of their life cycle. Roads can induce direct and indirect effects on animal reproductive rates success, affecting demographic parameters and population persistence. Specifically, the negative effects of roads on animal reproduction could be associated with increased mortality during mating season, acting as ecological traps during reproduction or reducing the probability of finding potential mating due to population isolation. Roads can also negatively affect embryo development and delay the hatching in some amphibian species. Direct and indirect negative effects of roads on animal reproduction can drive a decreasing animal fitness, as a consequence of lower quality of roadside habitats, or due to the presence of chemical contaminants associated with road network maintenance. The understanding of the main effects of roads on animal reproduction can help the implementation of science-based strategies to mitigate the negative effects of road networks on animal populations.