An investigation of the behaviour of guppies, Poecilia reticulata, in the wild reveals that sexual conflict varies markedly in different habitats. Males from high-predation sites in Trinidad (where the pike cichlid Crenicichla alta occurs) engage in less antipredator behaviour than females, have lower foraging rates than males from low-risk sites and are able to devote a greater proportion of their time to pursuing females and attempting sneaky matings. As a result, females in such locations receive approximately one sneaky mating attempt per minute. Female behaviour in high-predation sites is thus constrained not only by their own predator avoidance but also by sexual harassment which is itself an indirect consequence of risk. Sexual harassment is likely to compromise female choice and may have significant evolutionary consequences.