We sought to understand why many homeless people own pets despite the associated costs. Thematic analyses of interviews with seven homeless pet-owners indicated that interviewees perceived—not always accurately—that their pets limited their mobility and access to services. However, this was seen as a worthwhile cost for the companionship and sense of responsibility their pets provided, which increased resilience and enabled a reduction in substance abuse. Pet ownership also rendered interviewees psychologically vulnerable as the loss of a pet was highly traumatic and ignited coping mechanisms. We discuss the implications for homeless support services in the UK.