Children with autism might display unpredictable and volatile behavior that places them in considerable physical danger and creates stress for the family. Families of autistic children often have limited freedom and experience difficulty with everyday activities. In this qualitative ethology study, we examined the effect of integrating service dogs into ten families with an autistic child. Data included participant observation, video recordings of family—parent—dog interaction, and semistructured interviews with the parents. The themes were (a) the dog as a sentinel of safety, (b) gaining freedom through enhanced safety, facilitating public outings and family activities, and (c) improving social recognition and status, in which the presence of the dog promoted awareness of autism and affected social interaction. The triadic relationship between parent, autistic child, and service dog constantly evolves. This research provides valuable information for parents interested in having a service dog for their autistic child, and has implications for long-term human—animal companionship for children with special needs and their caregivers.