Emotion-related regulation is a topic of increasing interest among researchers, yet there is little agreement on ways to measure emotion regulation in young children. In this paper, we first consider important conceptual distinctions in regard to the different types of emotion-related regulation and control. Next, we describe a number of ways researchers have assessed children's regulation. We also present data from the Toddler Emotional Development project, in which laboratory-based measures of effortful regulation were used. In this section, we highlight the measures that show promise (and those that did not work well). Future directions for research on the measurement of effortful regulation are presented.