Blocks are one of the most popular playthings for children. The purpose of this article is to describe the use of block play in developing parent-child relations. This paper has two major parts. First, a brief historical overview highlights the critical roles of child's block play in learning and development. Block play contributes to children's cognitive development, social-emotional development, and motor development. Second, we discuss block play time as an opportunity to enhance parent-child relationships. A Reciprocal Model of Parent-Child Interaction is developed and discussed that involves four strategies: observing, listening and supporting, talking and extending, and understanding. Use of these strategies increases healthy relations and communications between parents and children in family settings. (Contains 1 figure.)