This review of 20 years of developmental research on Executive Functions (EF) offers a broad-brushstroke picture that touches on multiple issues including: (i) findings from typical and atypical groups, from infancy to adolescence; (ii) advances in assessment tools and in statistical analysis; (iii) the interplay between EF and other cognitive systems (e.g. those involved in children's developing understanding of mind, and in their processing of reward signals); (iv) integration of cognitive and neuroscience perspectives on EF; and (v) environmental factors that have either a positive influence (e.g. training/intervention programmes; parental scaffolding) or a negative influence (e.g. maltreatment, neglect, traumatic brain injury) on EF. Of the several themes to emerge from this review, two are particularly important; these concern the need to adopt developmental perspectives and the potential importance for intervention work of research on social influences on EF. Specifically, the review highlights both developmental continuities (e.g. in the correlates of EF) and contrasts (e.g. in the nature of EF and its neural substrates) and calls for research that compares developmental trajectories for EF in different groups (e.g. children with autism versus ADHD). In addition, findings from both family-based research and randomized controlled trials of school-based interventions highlight the importance of environmental influences on EF and so support the development of interventions to promote EF and hence improve children's academic and social outcomes.