A long-held notion of sexual selection theory is that only males enhance their reproductive success by mating with multiple mates. However, recent advances in molecular techniques for assigning paternity have revealed that polyandry, in which females mate with more than one male, is widespread among animals. Copulation is potentially costly to females due to time and energy expenses, exposure to predators increased risk of disease transmission and mechanical damage. Therefore, the maintenance of polyandry stands as one of the most topical, yet poorly understood, subjects in the field of evolutionary biology. In this talk I will outline the main theoretical arguments regarding the evolution of polyandry, and discuss how empirical studies with anuran amphibians have provided some key insights into the causes and consequences of this mating system. I will also briefly outline how an understanding of processes favouring the evolution of polyandry can have important conservation implications.