Humans have many kinds of relationships with domesticated animals. To maintain relationships interactions are needed. Interactions with animals may be beneficial for humans but may also be risky. Scientific literature on effects of human–animal relationships and interactions in a workplace, health-care and residential context has been reviewed to develop ideas about the effects farm animals can have on humans. Although there are quite a few studies, the variety of methods, the complexity of the material, differences in research goals and variable quality of the studies make that no general conclusions about the effect of animals on humans can be drawn. Nevertheless, when interactions with animals affect people, it may be expected that this will be similar for pets and farm animals.