Animals are important in human psychological and cultural life, and our relationships with other species are psychological and morally complicated. This special issue presents a series of original research articles concerning attitudes towards animals, the ethics of their treatment, the effects of companion animals on human health and psychological well-being, and the role that culture plays in our interactions with other species. The articles illustrate the scope of the new field of human-animal relationships, the variety of research approaches, and the implications of research findings for social policy.