This paper examines the roles that companion animals play in the lives of American families, and discusses how those roles change as families progress through the stages of the family life cycle. It highlights the importance of pets in the lives of children and the benefits they receive from such relationships. It also presents information regarding the role of a child that animals often assume within families that do not have children. This paper also discusses the impact that the death of a pet has on the family, and provides suggestions for social workers who assist families that have strong attachment to companion animals.