To effectively care for well or ill children, nurses must know something about how children think and what they are capable of comprehending. Nurses have traditionally based assumptions about children's cognitive abilities on a surface knowledge of Piaget's theory of cognitive development. Many recent researchers in the field of cognitive development have pointed out limitations in Piaget's theory and offer new ways of conceptualizing the way children think. In this article, I will identify limitations of Piaget's theory as it applies to preschool-aged children. Ideas of researchers using an information processing approach to understanding children's thinking will be described as alternative approaches to the understanding of preschool thought. I prescriptively postulate how research findings concerning cognition have implications for nurses working with young children.