Animals are considered to act as social substitute, allowing people with autism spectrums disorders (ASD), a cognitive disorder, with social withdrawal, first to establish bonds with them and second to extend these bonds to humans. However, clear scientific bases proving such effects are still lacking. As a first step, the present study describes the interactions between 190 subjects with ASD and their pets, and investigates the possible influence of the subject's age and of the pet species. On the one hand, parents reported that their 6-to-12 year-old children mainly interacted by physical contacts whereas adults with ASD mostly interacted with visual contact, both with dogs and cats. On the other hand, some environmental factors and pet characteristics seemed to modulate the relation described; for example, the relation between 6-to-9 year-old children with ASD and their dog seemed to be related to dog size and purchase origin. Such study could be considered as a first characterisation of the relation that subjects with ASD could develop with their pets and the basis for thoughts about what animals and how animals could potentially help developing cognitive or social skills in such children.