Effortful control (EC) and executive function (EF) are 2 constructs related to childrens self-regulation that have historically been the subject of research in separate fields, with EC primarily the focus of temperament research and EF the focus of cognitive neuroscience and clinical psychology. This article selectively reviews and compares the EC and EF literature. The review indicates considerable similarities and overlaps in the definitions, core components, and measurement of EC and EF. Differences between the 2 literatures seem to primarily reflect differences in research focus as influenced by each fields tradition rather than real differences in EC and EF as developmental constructs. Thus, developing an integrated theory of self-regulation encompassing the EC and EF perspectives is critical for reducing overlap and confusion in future research. The article provides a number of recommendations on how to integrate the theory and methodology of EC and EF in future research for (a) the components and organization of self-regulation, (b) the relation of self-regulation to childrens adaptive functions, (c) the neurological basis of self-regulation and its development, and (d) the development and evaluation of interventions targeting childrens self-regulation.