Challenging behavior is often a source of frustration for parents. Challenging behavior is defined as any behavior that interferes with children's learning and development, is harmful to children and to others, and puts a child at risk for later social problems or school failure (Bailey & Wolery, 1992; Kaiser & Rasminsky, 2003). Children's challenging behaviors can affect a family's ability to participate in home routines and community activities. When children engage in persistent challenging behavior, the importance of designing effective behavior interventions in collaboration with parents cannot be overstated. The purpose of this article is to help early childhood practitioners collaborate with parents to identify the purpose of challenging behaviors, determine effective strategies to address these behaviors, and create a behavior support plan that "fits" the needs of the child as well as the family. Guidelines for observing challenging behaviors and creating behavior support plans also are described. Throughout the article, examples are presented to illustrate ideas that are presented; however, these examples are not meant to be comprehensive or exhaustive. (Contains 3 tables.)